3,4-dihydro-2H-pyrazino[1,2-A]indol-1-one derivatives active as kinase inhibitors, process for their preparation and pharmaceutical compositions comprising them

ABSTRACT

Compounds which are 3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one derivatives or pharmaceutically acceptable salts thereof, their preparation process and pharmaceutical compositions comprising them are disclosed; these compounds are useful in the treatment of diseases caused by and/or associated with an altered protein kinase activity such as cancer, viral infection, prevention of AIDS development in HIV-infected individuals, cell proliferative disorders, autoimmune and neurodegenerative disorders; also disclosed is a process under Solid Phase Synthesis conditions for preparing the compounds of the invention and chemical libraries comprising a plurality of them.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of co-pending application having U.S. Ser. No. 12/934,422, filed on Sep. 24, 2012, which is a '371 of international application having Serial No. PCT/EP2009/053668, the contents of all of which are incorporated herein by reference.

The present invention relates to certain 8-amino derivatives of 3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one compounds, which modulate the activity of protein kinases. The compounds of this invention are therefore useful in treating diseases caused by dysregulated protein kinase activity. The present invention also relates to methods for preparing these compounds, combinatorial libraries thereof, pharmaceutical compositions comprising these compounds, and methods of treating diseases utilizing pharmaceutical compositions comprising these compounds.

The malfunctioning of protein kinases (PKs) is the hallmark of numerous diseases. A large share of the oncogenes and proto-oncogenes involved in human cancers code for PKs. The enhanced activities of PKs are also implicated in many non-malignant diseases, such as benign prostate hyperplasia, familial adenomatosis, polyposis, neuro-fibromatosis, psoriasis, vascular smooth cell proliferation associated with atherosclerosis, pulmonary fibrosis, arthritis, glomerulonephritis and post-surgical stenosis and restenosis.

PKs are also implicated in inflammatory conditions and in the multiplication of viruses and parasites. PKs may also play a major role in the pathogenesis and development of neurodegenerative disorders.

For a general reference to PKs malfunctioning or disregulation see, for instance, Current Opinion in Chemical Biology 1999, 3, 459-465 and Carcinogenesis 2008, 29, 1087-191.

3,4-Dihydro-2H-pyrazino[1,2-a]indol-1-one derivatives for the treatment of disorders of the central nervous system and obesity are disclosed in WO 2002/010169 and WO 2002/072584, all in the name of F. Hoffmann-La Roche A.-G. and Vernalis Research (Limited).

8-Oxy derivatives of 3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one for the treatment of obesity are disclosed in WO2007/065820 in the name of F. Hoffmann-La Roche A.-G. 7-Carmaboyl-derivatives of 3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one for the treatment of cytokine mediated diseases such as rheumatoid arthritis, inflammatory bowel disease and Alzheimer's disease are disclosed in US200627453, in the name of Boehringer Ingelheim Pharmaceuticals, Inc., USA.

The present inventors have now discovered that the new compounds of formula (I), described below, are kinase inhibitors and are thus useful in therapy as antitumor agents.

Accordingly, a first object of the present invention is to provide a 8-amino-3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one compound represented by formula (I):

-   wherein -   R is selected from the group consisting of —R^(a), —COR^(a),     —CONR^(a)R^(b), —SO₂R^(a) and —COOR^(a), and -   R1 is a group —NR^(c)R^(d) or —OR^(c), -   wherein R^(a), R^(b), R^(c) and R^(d), the same or different, are     each independently hydrogen or a group optionally further     substituted, selected from straight or branched C₁-C₆ alkyl, C₂-C₆     alkenyl or C₂-C₆ alkynyl, C₃-C₆ cycloalkyl or cycloalkyl C₁-C₆     alkyl, heterocyclyl or heterocyclyl C₁-C₆ alkyl, aryl or aryl C₁-C₆     alkyl, heteroaryl or heteroaryl C₁-C₆ alkyl or, taken together with     the nitrogen atom to which they are bonded, either R^(a) and R^(b)     as well as R^(c) and R^(d) may form an optionally substituted 3 to 7     membered heterocyclyl or heteroaryl, optionally containing one     additional heteroatom or heteroatomic group selected from S, O, N or     NH, -   and pharmaceutically acceptable salts thereof.

The present invention also provides methods of synthesizing the substituted 8-amino-3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one compounds, represented by formula (I), prepared through a process consisting of standard synthetic transformations.

The present invention also provides a method for treating diseases caused by and/or associated with dysregulated protein kinase activity, particularly PLK family, ABL, AKT1, ALK, AUR1, AUR2, BRK, CDC7/DBF4, CDK2/CYCA, CHK1, CK2, EE2FK, EGFR1, ERK2, FAK, FGFR1, FLT3, GSK3beta, IGFR1, IKK2, IR, JAK2, JAK3, KIT, LCK, MAPKAPK2, MET, MPS1, NEK6, NIM1, P38alpha, PAK-4, PDGFR, PDK1, PERK, PIM1, PKAalpha, PKCbeta, PLK1, RET, B-RAF, STLK2, SULU1, TRKA, VEGFR2, VEGFR3, ZAP70.

A preferred method of the present invention is to treat a disease caused by and/or is associated with dysregulated protein kinase activity selected from the group consisting of cancer, viral infection, prevention of AIDS development in HIV-infected individuals, cell proliferative disorders, autoimmune and neurodegenerative disorders.

Another preferred method of the present invention is to treat specific types of cancer including but not limited to: carcinoma such as bladder, breast, colon, kidney, liver, lung, including small cell lung cancer, esophagus, gall-bladder, ovary, pancreas, stomach, cervix, thyroid, prostate, and skin, including squamous cell carcinoma; hematopoietic tumors of lymphoid lineage including leukaemia, acute lymphocytic leukaemia, acute lymphoblastic leukaemia, B-cell lymphoma, T-cell-lymphoma, Hodgkin's lymphoma, non-Hodgkin's lymphoma, hairy cell lymphoma and Burkitt's lymphoma; hematopoietic tumors of myeloid lineage, including acute and chronic myelogenous leukemias, myelodysplastic syndrome and promyelocytic leukaemia; tumors of mesenchymal origin, including fibrosarcoma and rhabdomyosarcoma; tumors of the central and peripheral nervous system, including astrocytoma, neuroblastoma, glioma and schwannomas; other tumors, including mesothelioma, melanoma, seminoma, teratocarcinoma, osteosarcoma, xeroderma pigmentosum, keratoxanthoma, thyroid follicular cancer and Kaposi's sarcoma.

Another preferred method of the present invention is to treat specific cellular proliferation disorders such as, for example, benign prostate hyperplasia, familial adenomatosis polyposis, neurofibromatosis, psoriasis, vascular smooth cell proliferation associated with atherosclerosis, pulmonary fibrosis, arthritis, glomerulonephritis and post-surgical stenosis and restenosis.

In addition, the method of the present invention also provides tumor angiogenesis and metastasis inhibition, as well as treatment of organ transplant rejection and host versus graft disease.

In a further preferred embodiment, the method of the present invention further comprises subjecting the mammal in need thereof to a radiation therapy or chemotherapy regimen in combination with at least one cytostatic or cytotoxic agent. Moreover the invention provides an in vitro method for inhibiting protein kinase activity which comprises contacting the said protein kinase with an effective amount of a compound of formula (I).

The present invention also provides a pharmaceutical composition comprising one or more compounds of formula (I) or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable excipient, carrier or diluent.

The present invention also provides a pharmaceutical composition comprising a compound of formula (I) in combination with known cytostatic or cytotoxic agents, antibiotic-type agents, DNA damaging or intercalating agents, platin-based agents, alkylating agents, antimetabolite agents, hormonal agents, antihormonal agents such as antiestrogens, antiandrogens and aromatase inhibitors, immunological agents, interferon-type agents, cyclooxygenase inhibitors (e.g. COX-2 inhibitors), matrixmetalloprotease inhibitors, tyrosine kinase inhibitors, other kinase inhibitors, anti-growth factor receptor agents, anti-HER agents, anti-EGFR agents, anti-angiogenesis agents (e.g. angiogenesis inhibitors), farnesyl transferase inhibitors, ras-raf signal transduction pathway inhibitors, cell cycle inhibitors, other cdks inhibitors, tubulin binding agents, topoisomerase I inhibitors, topoisomerase II inhibitors, inhibitors of kinesins, therapeutic monoclonal antibodies, inhibitors of mTOR, histone deacetylase inhibitors, inhibitors of hypoxic response and the like.

Additionally, the invention provides a product or kit comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof, as defined above, or pharmaceutical compositions thereof and one or more chemotherapeutic agents, as a combined preparation for simultaneous, separate or sequential use in anticancer therapy.

In yet another aspect the invention provides a compound of formula (I) or a pharmaceutically acceptable salt thereof, as defined above, for use as a medicament. Moreover the invention provides the use of a compound of formula (I) or a pharmaceutically acceptable salt thereof, as defined above, in the manufacture of a medicament for treating diseases caused by and/or associated with an altered protein kinase activity.

Finally, the invention provides a compound of formula (I) or a pharmaceutically acceptable salt thereof, as defined above, for use in a method for treating diseases caused by and/or associated with an altered protein kinase activity.

Unless otherwise specified, when referring to the compounds of formula (I) per se as well as to any pharmaceutical composition thereof or to any therapeutic method of treatment comprising them, the present invention includes all the solvates, hydrates, complexes, metabolites, prodrugs, carriers, N-oxides and pharmaceutically acceptable salts of the compounds of this invention.

“Solvate” means a physical association of a compound of this invention with one or more solvent molecules. This physical association involves varying degrees of ionic and covalent bonding, including hydrogen bonding. In certain instances the solvate will be capable of isolation, for example when one or more solvent molecules are incorporated in the crystal lattice of the crystalline solid. “Solvate” encompasses both solution-phase and isolatable solvates. Non-limiting examples of suitable solvates include ethanolates, methanolates, and the like.

“Hydrate” is a solvate wherein the solvent molecule is H₂O.

A “metabolite” of a compound of formula (I) is any compound into which this same compound of formula (I) is converted in vivo, for instance upon administration to a mammal in need thereof. Typically, without however representing a limiting example, upon administration of a compound of formula (I), this same derivative may be converted into a variety of compounds, for instance including more soluble derivatives like hydroxylated derivatives, which are easily excreted. Hence, depending upon the metabolic pathway thus occurring, any of these hydroxylated derivatives may be regarded as a metabolite of the compounds of formula (I).

The term “prodrug”, as employed herein, denotes a compound that is a drug precursor, which, upon administration to a subject, undergoes chemical conversion by metabolic or chemical processes to yield a compound of formula (I) or a salt and/or solvate thereof. A discussion of prodrugs is provided in T. Higuchi and V. Stella, Pro-drugs as Novel Delivery Systems (1987) Volume 14 of the A.C.S. Symposium Series, and in Bioreversible Carriers in Drug Design, (1987) Edward B. Roche, ed., American Pharmaceutical Association and Pergamon Press.

All forms of chiral isomers or other forms of isomers including enantiomers and diastereomers, are intended to be covered herein. Compounds containing a chiral center may be used as a racemic mixture or as an enantiomerically enriched mixture, or the racemic mixture may be separated using well-known techniques and an individual enantiomer may be used alone.

In cases wherein compounds may exist in tautomeric forms, such as keto-enol tautomers, each tautomeric form is contemplated as being included within this invention whether existing in equilibrium or predominantly in one form.

In the present description, unless otherwise indicated, with the term “straight or branched C₁-C₆ alkyl” we intend any group such as, for instance, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, and the like. With the term “straight or branched C₂-C₆ alkenyl” or “straight or branched C₂-C₆ alkynyl” we intend any of the unsaturated alkenyl or alkynyl groups with from 2 to 6 carbon atoms for instance including vinyl, allyl, 1-propenyl, isopropenyl, 1-, 2- or 3-butenyl, pentenyl, hexenyl, ethynyl, 1- or 2-propynyl, butynyl, pentynyl, hexynyl, and the like.

With the term “C₃-C₆ cycloalkyl” we intend, unless otherwise specified, 3- to 6-membered all-carbon monocyclic ring, which may contain one or more double bonds but does not have a completely conjugated π-electron system. Examples of cycloalkyl groups, without limitation, are cyclopropane, cyclobutane, cyclopentane, cyclopentene, cyclohexane, cyclohexene and cyclohexadiene.

With the term “heterocyclyl” we intend a 3- to 7-membered, saturated or partially unsaturated carbocyclic ring where one or more carbon atoms are replaced by heteroatoms such as nitrogen, oxygen and sulfur. Non limiting examples of heterocyclyl groups are, for instance, pyrane, pyrrolidine, pyrroline, imidazoline, imidazolidine, pyrazolidine, pyrazoline, thiazoline, thiazolidine, dihydrofuran, tetrahydrofuran, 1,3-dioxolane, piperidine, piperazine, morpholine and the like.

With the term “aryl” we intend a mono-, bi- or poly-carbocyclic hydrocarbon with from 1 to 4 ring systems, optionally further fused or linked to each other by single bonds, wherein at least one of the carbocyclic rings is “aromatic”, wherein the term “aromatic” refers to completely conjugated π-electron bond system. Non limiting examples of such aryl groups are phenyl, α- or β-naphthyl or biphenyl groups.

With the term “heteroaryl” we intend aromatic heterocyclic rings, typically 5- to 7-membered heterocycles with from 1 to 3 heteroatoms selected among N, O or S; the heteroaryl ring can be optionally further fused or linked to aromatic and non-aromatic carbocyclic and heterocyclic rings. Not limiting examples of such heteroaryl groups are, for instance, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolyl, imidazolyl, thiazolyl, isothiazolyl, pyrrolyl, phenyl-pyrrolyl, furyl, phenyl-furyl, oxazolyl, isoxazolyl, pyrazolyl, thienyl, benzothienyl, isoindolinyl, benzoimidazolyl, quinolinyl, isoquinolinyl, 1,2,3-triazolyl, 1-phenyl-1,2,3-triazolyl, 2,3-dihydroindolyl, 2,3-dihydrobenzofuranyl, 2,3-dihydrobenzothiophenyl; benzopyranyl, 2,3-dihydrobenzoxazinyl, 2,3-dihydroquinoxalinyl and the like.

According to the meanings provided to R^(a), R^(b), R^(c) and R^(d), any of the above groups may be further optionally substituted in any of their free positions by one or more groups, for instance 1 to 6 groups, selected from: halogen, nitro, oxo groups (═O), carboxy, cyano, C₁-C₆ alkyl, polyfluorinated alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl, aryl, heteroaryl; amino groups and derivatives thereof such as, for instance, alkylamino, dialkylamino, arylamino, diarylamino, ureido, alkylureido or arylureido; carbonylamino groups and derivatives thereof such as, for instance, formylamino, alkylcarbonylamino, alkenylcarbonylamino, arylcarbonylamino, alkoxycarbonylamino; hydroxy groups and derivatives thereof such as, for instance, alkoxy, polyfluorinated alkoxy, aryloxy, alkylcarbonyloxy, arylcarbonyloxy, cycloalkenyloxy or alkylideneaminoxy; carbonyl groups and derivatives thereof such as, for instance, alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, cycloalkyloxycarbonyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl; sulfurated derivatives such as, for instance, alkylthio, arylthio, alkylsulfonyl, arylsulfonyl, alkylsulfonyl, arylsulfinyl, arylsulfonyloxy, aminosulfonyl, alkylaminosulfonyl or dialkylaminosulfonyl.

In their turn, whenever appropriate, each of the above substituents may be further substituted by one or more of the aforementioned groups.

In the present description, unless otherwise specified, with the term “cyano” we intend a —CN residue.

With the term “nitro” we intend a —NO₂ group.

With the term “halogen” we intend a fluorine, chlorine, bromine or iodine atom.

With the term “polyfluorinated alkyl or alkoxy” we intend a straight or branched C₁-C₆ alkyl or alkoxy group as above defined, wherein more than one hydrogen atom is replaced by fluorine atoms such as, for instance, trifluoromethyl, trifluoromethoxy, 2,2,2-trifluoroethyl, 2,2,2-trifluoroethoxy, 1,2-difluoroethyl, 1,1,1,3,3,3-hexafluoropropyl-2-yl, and the like.

From all of the above, it is clear to the skilled man that any group which name has been identified as a composite name such as, for instance, cycloalkylalkyl, arylalkyl, heterocyclylalkyl, alkoxy, alkylthio, aryloxy, arylalkyloxy, alkylcarbonyloxy and the like, has to be intended as conventionally construed from the parts to which it derives. So far, as an example, the terms heterocyclyl-alkyl and cycloalkyl-alkyl stand for a straight or branched alkyl group being further substituted by a heterocyclic or cycloalkyl group, respectively, as above defined.

The term “pharmaceutically acceptable salts” embraces salts commonly used to form alkali metal salts and to form addition salts of free acids or free bases. The nature of the salt is not critical, provided that it is pharmaceutically acceptable. Suitable pharmaceutically acceptable acid addition salts of the compounds of the present invention may be prepared from an inorganic acid or from an organic acid. Examples of such inorganic acids are hydrochloric, hydrobromic, hydroiodic, nitric, carbonic, sulfuric, and phosphoric acid. Appropriate organic acids may be selected from aliphatic, cycloaliphatic, aromatic, araliphatic, heterocyclic, carboxylic and sulfonic classes of organic acids, examples of which are formic, acetic, trifluoroacetic, propionic, succinic, glycolic, gluconic, lactic, malic, fumaric, tartaric, citric, ascorbic, glucuronic, maleic, fumaric, pyruvic, aspartic, glutamic, benzoic, anthranilic, mesylic, salicylic, p-hydroxybenzoic, phenylacetic, mandelic, embonic (pamoic), methanesulfonic, ethanesulfonic, benzenesulfonic, pantothenic, toluenesulfonic, 2-hydroxyethanesulfonic, sulfanilic, stearic, cyclohexylaminosulfonic, algenic, hydroxybutyric, galactaric and galacturonic acid. Suitable pharmaceutically acceptable base addition salts of the compounds of the present invention include metallic salts made from aluminum, calcium, lithium, magnesium, potassium, sodium and zinc or organic salts made from N,N′-dibenzylethylenediamine, chloroprocaine, choline, diethanolamine, ethylenediamine, meglumine (N-methyl-glucamine) and procaine. All of these salts may be prepared by conventional means from the corresponding compounds of the present invention, for instance by reacting them with the appropriate acid or base.

A preferred class of compounds of formula (I) are the compounds wherein:

-   R1 is a group —NR^(c)R^(d) and R^(c) and R^(d) are both hydrogen     atoms or one of them is a hydrogen atom and the remaining one of     R^(c) or R^(d) is a straight or branched C₁-C₆ alkyl or C₂-C₆     alkenyl group or it is an optionally substituted aryl or arylalkyl     group.

Another preferred class of compounds of formula (I) are the compounds wherein:

-   R is a group R^(a) wherein R^(a) is hydrogen, or is a group     —SO₂R^(a) wherein R^(a) is straight or branched C₁-C₆ alkyl or     optionally substituted aryl or arylalkyl.

A further preferred class of compounds of formula (I) are the compounds wherein:

-   R is a group —COR^(a) wherein R^(a) is a straight or branched C₁-C₆     alkyl, cycloalkyl or optionally substituted aryl or arylalkyl group.

A more preferred class of compounds of formula (I) are the compounds wherein:

-   R is a group —CONR^(a)R^(b) wherein one of R^(a) and R^(b) are     hydrogen and the other is straight or branched C₁-C₆ alkyl,     optionally substituted aryl or arylalkyl group.

For a reference to any specific compound of formula (I) of the invention, optionally in the form of pharmaceutically acceptable salts, see the experimental section.

The intermediate compound of formula (VII):

wherein R1 is as defined above, is novel and hence represents a further object of the invention.

The present invention also provides a process for the preparation of a compound of formula (I) as defined above, characterized in that the process comprises:

-   a) hydrolysing under basic or acidic conditions the compound of     formula (II):

-   b) reacting the resultant compound of formula (III) or a salt     thereof:

-   with 2,2-dimethoxy-ethylamine, after activation of the carboxyl     group; -   c) deprotecting under acidic conditions the resultant compound of     formula (IV):

-   d) reacting under basic conditions the resultant compound of formula     (V):

-   with a phosphonate of formula (VI):

-   wherein Alk is C₁-C₆ alkyl and R^(c) is C₁-C₆ alkyl; -   optionally converting the resultant compound of formula (VII):

-   wherein R1 represents OR^(c) and R^(c)is C₁-C₆ alkyl, into another     compound of formula (VII) by replacing the —OR^(c) group with a     different group among those represented by R1; -   e) reducing said compound of formula (VII) to give a compound of     formula (I) or a salt thereof:

-   wherein R1 is OR^(c) and R^(c) is C₁-C₆ alkyl; -   optionally separating the resultant compound of formula (I) into the     single isomers; converting the resultant compound of formula (I)     into a different compound of formula (I) by derivatising the amino     moiety, and/or by replacing the group —OR^(c) with a different group     among those represented by R1, and/or into a pharmaceutically     acceptable salt if desired.

The present invention further provides a process for the preparation of a compound of formula (I) as defined above, characterized in that the compound of formula (I) prepared in steps from a) to e) described above, is converted into another compound of formula (I) by derivatising the amino moiety, said derivatization being carried out by one or more of the following reactions:

-   f) reacting a compound of formula (I) wherein R is hydrogen and R1     is —OR^(c) and R^(c) is C₁-C₆ alkyl, according to any one of the     alternative steps: -   f.1) with an acid or an acyl halide of formula (VIII):     R^(a)COZ  (VIII) -   wherein R^(a) is as defined above and Z is a halogen or a group —OH,     to give a compound of formula (I):

-   wherein R1 is —OR^(c) and R^(c) is C₁-C₆ alkyl and R^(a) are as     defined above; or -   f.2) with an isocyanate of formula (IX):     R^(a)NCO  (IX) -   wherein R^(a) is as defined above, to give a compound of formula     (I):

-   wherein R1 is —OR^(c) and R^(c) is C₁-C₆ alkyl and R^(a) are as     defined above; or -   f.3) with a sulphonyl halide of formula (X):     R^(a)SO₂Z′  (X) -   wherein R^(a) is as defined above and Z′ is a halogen, to give a     compound of formula (I):

-   wherein R1 is —OR^(c) and R^(c) is C₁-C₆ alkyl and R^(a) are as     defined above; or -   f.4) with a halogen carbonate of formula (XI):     R^(a)OCOZ′  (XI) -   wherein R^(a) and Z′ are as defined above, to give a compound of     formula (I):

-   wherein R1 is —OR^(c) and R^(c) is C₁-C₆ alkyl and R^(a) are as     defined above; or -   f.5) with an amine of formula (XII):     HNR^(a)R^(b)  (XII) -   wherein R^(a) and R^(b) are as defined above, in presence of a     suitable chloroformate, to give a compound of formula (I):

-   wherein R1 is —OR^(c) and R^(c) is C₁-C₆ alkyl, and R^(a) and R^(b)     are as defined above; or -   (f.6) with a suitable aldehyde or ketone derivative of formula     (XIII):     R^(a)—CO—R^(a)  (XIII) -   wherein each of R^(a), the same or different, are as defined above,     to give a compound of formula (I):

-   wherein R1 is —OR^(c) and R^(c) is C₁-C₆ alkyl and each of R^(a),     the same or different, are as defined above; or -   (f.7) with an halide of formula (XIV):     R^(a)—Z′  (XIV) -   wherein R^(a) and Z′ are as defined above, to give a compound of     formula (I):

-   wherein R1 is —OR^(c) and R^(c) is C₁-C₆ alkyl and R^(a) are as     defined above; -   optionally separating the resultant compound of formula (I) into the     single isomers; -   converting the resultant compound of formula (I) into a different     compound of formula (I) by replacing the group —OR^(c) with a     different group among those represented by R1, and/or into a     pharmaceutically acceptable salt if desired.

The present invention further provides a process for the preparation of a compound of formula (I) as defined above, characterized in that the compound of formula (I) is converted into another compound of formula (I), said conversion is carried out by one or more of the following reactions:

-   g.1) acid or basic hydrolysis of a compound of formula (I) wherein     R1 is —OR^(c) and R^(c) is C₁-C₆ alkyl, to give the corresponding     compound of formula (I) wherein R1 is —OR^(c) and R^(c) is hydrogen,     or the corresponding salt; -   g.2) transesterification of a compound of formula (I) wherein R1 is     —OR^(c) and R^(c) is C₁-C₆ alkyl, by reactions with a compound of     formula (XV):     R^(c)—OH  (XV) -   to give the corresponding compound of formula (I) wherein R1 is     —OR^(c) and R^(c) is a different C₁-C₆ alkyl; -   g.3) aminolysis of a compound of formula (I) wherein R₁ is —OR^(c)     and R^(c) is C₁-C₆ alkyl, by reaction with a compound of formula     (XVI):     HNR^(c)R^(d)  (XVI) -   to give the corresponding compound of formula (I) wherein R1 is     —NR^(c)R^(d); -   g.4) esterification of a compound of formula (I) wherein R1 is a     group —OH or its corresponding salt, by reactions with a compound of     formula (XV) as defined above, to give the corresponding compound of     formula (I) wherein R1 is —OR^(c); -   g.5) amidation of a compound of formula (I) wherein R1 is a group     —OH or its corresponding salt, by reaction with a compound of     formula (XVI) as defined above, to give the corresponding compound     of formula (I) wherein R1 is —NR^(c)R^(d).

The present invention further provides a process for the preparation of a compound of formula (I) as defined above, characterized in that the compound of formula (VII) as defined above, is converted into another compound of formula (VII), said conversions are carried out by one or more of the following reactions:

-   h.1) acid or basic hydrolysis of a compound of formula (VII) wherein     R1 is —OR^(c) and R^(c) is C₁-C₆ alkyl, to give a compound of     formula (VII) wherein R1 is —OR^(c) and R^(c) is hydrogen, or the     corresponding salt; -   h.2) transesterification of a compound of formula (VII) wherein R1     is —OR^(c) and R^(c) is C₁-C₆ alkyl, by reaction with a compound of     formula (XV) as defined above, to give a compound of formula (VII)     wherein R1 is —OR^(c) and R^(c) is a different C₁-C₆ alkyl; -   h.3) amidation of a compound of formula (VII) wherein R1 is —OR^(c)     and R^(c) is C₁-C₆ alkyl, by reaction with a compound of     formula (XVI) as defined above, to give a compound of formula (VII)     wherein R1 is —NR^(c)R^(d); -   h.4) esterification of a compound of formula (VII) wherein R1 is     —OR^(c) and R^(c) is hydrogen, or the corresponding salt, by     reaction with a compound of formula (XV) as defined above, to give a     compound of formula (VII) wherein R1 is —OR^(c) and R^(c) is     different from hydrogen; -   h.5) amidation of a compound of formula (VII) wherein R1 is —OR^(c)     and R^(c) is hydrogen, by reaction with a compound of formula (XVI)     as defined above, to give a compound of formula (VII) wherein R1 is     —NR^(c)R^(d .)

From all of the above, it is clear to the skilled person that if a compound of formula (I) or (VII), prepared according to the above processes comprehensive of any variant thereof, is obtained as an admixture of isomers, their separation into the single isomers of formula (I), carried out according to conventional techniques, is still within the scope of the present invention.

Likewise, the conversion of a compound of formula (I) into a pharmaceutically acceptable salt thereof or, alternatively, the conversion into the free compound (I) of a corresponding salt, according to procedures well-known in the art, is still within the scope of the invention.

When preparing the compounds of formula (I) according to any variant of the process, which are all to be intended as within the scope of the invention, optional functional groups within the starting materials, the reagents or the intermediates thereof, and which could give rise to unwanted side reactions, need to be properly protected according to conventional techniques.

The starting materials of the process object of the present invention, comprehensive of any possible variant, as well as any reactant thereof, are known compounds and if not commercially available per se may be prepared according to well-known methods. Likewise, the compounds of formula (II), (VI), (VIII), (IX), (X), (XI), (XII), (XIII), (XIV), (XV), (XVI), are known or easily obtained according to known methods, for a general reference see: Smith, Michael—March's Advanced Organic Chemistry: reactions mechanisms and structure—5^(th) Edition, Michael B. Smith and Jerry March, John Wiley & Sons Inc., New York (NY), 2001.

According to step (a) of the process, the hydrolysis of the compound of formula (II) under basic or acidic conditions can be carried out in a variety of ways, according to conventional methods for hydrolysing esters derivatives. Preferably, the reaction is carried out in the presence of aqueous lithium hydroxide, methanol and tetrahydrofuran, at a temperature ranging from room temperature to about 90° C. and for a time from 4 hours to one day. According to the operative conditions being employed, the compound of formula (III) could be obtained either in its acidic form or, alternatively, as a salt. According to step (b) of the process, the conversion of the compound of formula (III) into the corresponding amido derivative of formula (IV), can be carried out in a variety of ways, according to conventional methods for obtaining amido derivatives from the corresponding acids. For example the reaction may be carried out by reaction with 2,2-dimethoxy-ethylamine after activation of the carboxylic function of the compound of formula (III) by reaction with thionyl chloride, oxalyl chloride or alternatively in the presence of a suitable condensing agent, for instance dicyclohexylcarbodiimide (DCC), 1-ethyl-3-(3′-dimethylaminopropyl)carbodiimide (EDC), O-benzotriazolyl-tetramethyl-isouronium tetrafluoroborate (TBTU) or benzotriazol-1-yloxy-tripyrrolidino-phosphonium hexafluorophosphate (PyBOP). Preferably, the reaction is carried out using thionyl chloride in dioxane as solvent and the isolated acyl chloride, by volatiles removal, is reacted with 2,2-dimethoxy-ethylamine under well-known Schotten-Baumann conditions.

According to step (c) of the process, the deprotection of the di-methyl acetal of the compound of formula (IV) can be carried out in a variety of ways, according to conventional methods for acetal removal. Preferably, the reaction is carried out in the presence of a suitable solvent, for instance in acetone and water, under acidic conditions, for instance in the presence of a mineral acid, preferably hydrochloric acid.

According to step (d) of the process, the reaction of the compound of formula (V) with compound of formula (VI) can be carried out in a variety of ways, according to conventional methods for Horner-Emmons reaction. Preferably, the reaction is carried out using different organic or inorganic bases such as lithium hydroxide in tetrahydrofuran and water or 1,8-diazabicyclo[5.4.0]undec-7-ene in acetonitrile with the trimethyl phosphonoacetate of formula (VI).

According to step (e) of the process, the reduction of the nitro group of the compound of formula (VII) to give a compound of formula (I), can be carried out in a variety of ways, according to conventional methods for reducing nitro group to the corresponding amino derivative. Preferably the reaction is carried out in the presence of tin (II) chloride in dimethylformamide (DMF) at room temperature for a time ranging from 4 to 24 hours.

According to any one of steps (f.1) to (f.7) the preparation of functionalized amino derivatives starting from the corresponding amine can be carried out in a variety of ways, according to conventional methods.

Preferably, according to step (f.1), (f.3) and (f.4) of the process, the compound of formula (I) is dissolved in a suitable solvent such as dichloromethane, dimethylformamide, tetrahydrofuran, dioxane or the like, and a suitable base such as triethylamine, diisopropylethylamine or sodium carbonate is added therein.

The compounds of general formula (VIII), (X) or (XI) are then added and the mixture stirred for a time of about 2 hours to about 15 hours, at a temperature ranging from about 20° C. to about 80° C. A suitable catalyst such as dimethylamino pyridine may be optionally used.

Preferably according to step (f.2) of the process, the reaction conditions are the same as above reported for steps (f.1), (f.3) and (f.4) except that the base may not be required. The compound of general formula (IX) is then added and the mixture stirred as reported above for steps (f.1), (f.3) and (f.4).

Preferably according to step (f.5) of the process, the compound of formula (I) is reacted with an amino derivative of formula (XII) after activation by reaction with a suitable chloroformate such as, for instance, 4-nitrophenylchloroformate. The reaction is carried out in a suitable solvent such as a halogenated hydrocarbon, preferably dichloromethane, in the presence of a base such as, for instance, diisopropylethylamine or triethylamine and by working at room temperature.

Preferably according to step (f.6) of the process, the compound of formula (I) is with reacted with an aldehyde or ketone derivative of formula (XIII). It is clear to the skilled man that by employing an aldehyde derivative of formula (XIII) wherein one of the two R^(a) is a hydrogen atom, the corresponding derivatives wherein R is —CH₂R^(a) are obtained. Likewise, by employing a ketone derivative, compounds having R as —CH(R^(a))R^(a) are obtained, wherein each R^(a) is, independently from each other, as set forth above but other than hydrogen. The reaction can be carried out in a variety of ways, according to conventional methods for reductive amination. Preferably, the reaction is carried out by reaction with an aldehyde or ketone derivative of formula (XIII) in a suitable solvent such as tetrahydrofuran and after a time from 2 to 12 hours by addition of a reducing agent such as sodium cyanoborohydride or sodium triacetoxyborohydride.

Preferably according to step (f.7) of the process, the compound of formula (I) is reacted with an aromatic iodide or bromide of formula (XIV) in the presence of a suitable catalyst, for instance a palladium catalyst like palladium acetate or Pd₂(dba)₃, and of a suitable ligand. See, for a general reference to the above arylation reaction and operative conditions thereof also inclusive of solvents, catalysts and ligands, J. Am. Chem. Soc., (2003), 125, 6653-55; JOC (2001), 66, 2560-2565; and JOC (2002), 67, 6479-6486.

According to any one of steps (g.1) to (g.5) the conversion of a compound of formula (I) into another compound of formula (I) can be carried out in a variety of ways, according to conventional methods.

Preferably according to step (g.1) of the process, the hydrolysys of a compound of formula (I) wherein R1 is —OCH₃, to give the corresponding compound of formula (I) wherein R1 is —OH is carried out under acidic or basic conditions. Preferably, the reaction is carried out as described under step (a). According to the operative conditions being employed, the compound of formula (I) wherein R1 is —OH could be obtained either in its acidic form or, alternatively, as a salt.

Preferably according to step (g.2) of the process, the transesterification of a compound of formula (I) wherein R1 is —OCH₃, to give the corresponding compound of formula (I) wherein R1 is —OR^(c) and R^(c) is an alkyl different from methyl, is carried out by reaction with a compound of formula (XV) in an appropriate solvent, such as the compound of formula (XV) itself or dioxane at the refluxing temperature, optionally in the presence of a suitable metal based catalysts, like dibutylin oxide or titanium alkoxides such as, for instance, titanium (IV) ethoxide, titanium (IV) isopropoxide and the like.

Preferably according to step (g.3) of the process, the aminolysis of a compound of formula (I) wherein R1 is —OCH₃, to give the corresponding compound of formula (I) wherein R1 is —NR^(c)R^(d) is carried out in an appropriate solvent such as dioxane or dichloromethane optionally in the presence of a suitable metal based catalysts, like trimethyl aluminium.

Preferably according to step (g.4) of the process, the esterification of a compound of formula (I) wherein R1 is a group —OH to give the corresponding compound of formula (I) wherein R1 is —OR^(c) is carried out in the presence of a suitable condensing agent, for instance dicyclohexylcarbodiimide (DCC), 1-ethyl-3-(3′-dimethylaminopropyl)-carbodiimide (EDC), O-benzotriazolyltetramethylisouronium tetrafluoroborate (TBTU) or benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate (PyBOP), in an appropriate solvent such as dichloromethane, dimethylformamide.

Preferably according to step (g.5) of the process, the amidation of a compound of formula (I) wherein R1 is a group —OH to give the corresponding compound of formula (I) wherein R1 is —NR^(c)R^(d) can be carried out in a variety of ways, according to conventional methods for obtaining amido derivatives from the corresponding acids. Preferably, the reaction is carried out by reaction with compound of formula (XVI) after activation of the carboxylic function of the compound of formula (I) by reaction with thionyl chloride, oxalyl chloride or alternatively in the presence of a suitable condensing agent, for instance dicyclohexylcarbodiimide (DCC), 1-ethyl-3-(3′-dimethylaminopropyl)carbodiimide (EDC), O-benzotriazolyltetramethylisouronium tetrafluoroborate (TBTU) or benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate (PyBOP), in an appropriate solvent such as dichloromethane, and/or dimethylformamide.

According to any one of steps (h.1) to (h.5) the conversion of a compound of formula (VII) into another compound of formula (VII) can be carried out in a variety of ways, according to conventional methods.

Preferably it is carried out as described under the steps from (g.1) to (g.5).

In addition to the above, the compounds of formula (I) may be advantageously prepared according to combinatorial chemistry techniques widely known in the art, by accomplishing the aforementioned reactions between the intermediates in a serial manner and by working under solid-phase-synthesis (SPS) conditions.

As an example, the intermediate carboxy ester derivatives of formula (VII), wherein R1 represents OR^(c) and R^(c is) C₁-C₆ alkyl, being obtained in step (d) of the above processes, can be first converted into the free carboxy acid derivative by means of hydrolysis carried out according to conventional methods, then easily supported onto a polymeric resin, for instance through the formation of a carboxamido group.

The intermediate thus supported may be subsequently reacted according to the remaining steps of the process.

The above synthetic pathway can be summarized as follows:

Any of the above reactions is carried out according to known methods, by working as formerly reported, and allows to obtain compounds of formula (I) as set forth above. Preferably, the above resin is a commercially available polystyrenic resin including, for instance, Wang resin, Trityl resin, Cl-trityl resin, Rink amide resin, Tentagel OH resin and derivatives thereof.

According to a preferred embodiment of the invention, the polystyrenic resin is a derivatized formyl polystyrenic resin which may be obtained by reacting a commercially available formyl polystyrenic resin, e.g. 4-(4-formyl-3-methoxyphenoxy)butyryl AM resin, with a suitable amino derivative under reductive conditions, for instance in the presence of sodium triacetoxyborohydride and derivatives thereof, substantially as follows:

The reaction may be carried out in a suitable solvent such as tetrahydrofuran and in the presence of acetic acid.

The polymer-supported-amino derivatives thus obtained, particularly those, which are referable to as derivatized formyl polystyrenic resin above, are widely known in the art. In general, amines loaded onto formylpolystyrenic resins also known as Acid Sensitive MethoxyBenzaldehyde polystirene resins (AMEBA resin) are prepared by standard reductive amination in the presence of an excess of amine in TMOF/DCE and NaBH(OAc)₃ or AcOH/DMF and NaCNBH₃, for instance as reported in Tetrahedron Letters (1997), 38, 7151-7154; J. Am. Chem. Soc. (1998), 120, 5441; and Chem. Eur. J. (1999), 5, 2787.

Therefore, it is a further object of the present invention a process for preparing the compounds of formula (I), and the pharmaceutically acceptable salts thereof, which process comprises:

-   i) hydrolyzing under acid or basic conditions the compound of     formula (VII) wherein R1 represents OR^(c) and R^(c) is C₁-C₆ alkyl; -   j) reacting the resultant acid derivative with a derivatized formyl     polystyrenic resin of formula (XVII):     (P)—CH₂—NHR^(c)  (XVII) -   wherein (P) is the resin and R^(c) is as defined above; -   k) reacting of the resultant compound of formula (XVIII):

-   wherein (P) and R^(c) are as described above, with a suitable     reducing agent such as chromium (II) chloride, tetrabutylammonium     hydrogen sulfide or tin (II) chloride; and -   l) reacting the resultant compound of formula (XIX):

-   wherein (P) and R^(c) are as described above, as described under any     one of steps from (f.1) to (f.7); -   m) cleaving the resin under acidic conditions from the resultant     compound of formula (XX):

-   to give a compound of formula (I), wherein R is as defined above and     R1 is —NHR^(c), -   wherein R^(c) is as defined above, optionally separating the     resultant compound of formula (I) into the single isomers;     converting the resultant compound of formula (I) into a different     compound of formula (I) and/or into a pharmaceutically acceptable     salt if desired.

According to step (i) of the process, the hydrolysis of a compound of formula (VII) wherein R₁ is —OCH₃, to give the corresponding compound of formula (VII) wherein R1 is —OH is carried out as described under step (h.1).

According to step (j) of the process, the reaction with the polystyrene resin is performed in a suitable solvent, for instance NMP, in the presence of diisopropylethylamine (DIPEA) and of a suitable condensing agent such as, for instance, 1-ethyl-3-(3′-dimethylaminopropyl)carbodiimide (EDC) or O-benzotriazolyl tetramethylisouronium tetrafluoroborate (TBTU).

According to step (k) of the process, the supported compound of formula (XVIII) is reduced to obtain the corresponding amino derivative; the reaction is carried out in the presence of tin (II) chloride in dimethylformamide (DMF) at room temperature for a time ranging from 4 to 24 hours.

According to step (l), the supported compound of formula (XIX) is optionally further reacted to give to a variety of compounds functionalised in position 5 of the 3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one ring, as described under any one of steps from (f.1) to (f.7).

According to step (m), the cleavage of the resin is performed under acidic conditions in the presence of suitable acids such as, for instance, hydrochloric, trifluoroacetic, methanesulfonic or p-toluensulfonic acid. Preferably the reaction is carried out using trifluoroacetic acid in dichloromethane as solvent.

Clearly, by working according to combinatorial chemistry techniques as formerly indicated, a plurality of compounds of formula (I) may be obtained.

Hence, it is a further object of the present invention a library of two or more compounds of formula (I)

-   wherein -   R is selected from the group consisting of —R^(a), —COR^(a),     —CONR^(a)R^(b), —SO₂R^(a) and —COOR^(a), and R1 is a group     —NR^(c)R^(d) or —OR^(c), wherein R^(a), R^(b), R^(c) and R^(d), the     same or different, are each independently hydrogen or a group     optionally further substituted, selected from straight or branched     C₁-C₆ alkyl, C₂-C₆ alkenyl or C₂-C₆ alkynyl, C₃-C₆ cycloalkyl or     cycloalkyl C₁-C₆ alkyl, heterocyclyl or heterocyclyl C₁-C₆ alkyl,     aryl or aryl C₁-C₆ alkyl, heteroaryl or heteroaryl C₁-C₆ alkyl or,     taken together with the nitrogen atom to which they are bonded,     either R^(a) and R^(b) as well as R^(c) and R^(d) may form an     optionally substituted 3 to 7 membered heterocyclyl or heteroaryl,     optionally containing one additional heteroatom or heteroatomic     group selected from S, O, N or NH, and pharmaceutically acceptable     salts thereof.

According to a preferred embodiment of the invention, the aforementioned library comprises the compounds of formula (I) wherein R₁ is a group —NR^(c)R^(d) and R^(c) and R^(d) are both hydrogen atoms or one of them is a hydrogen atom and the remaining one of R^(c) or R^(d) is a straight or branched C₁-C₆ alkyl or C₂-C₆ alkenyl group or it is an optionally substituted aryl or arylalkyl group.

Also preferred is a library of compounds of formula (I) wherein R is either a group R^(a) with R^(a) as a hydrogen atom or a group —SO₂R^(a) with R^(a) as a straight or branched C₁-C₆ alkyl group or optionally substituted aryl or arylalkyl group; and R₁ is as above defined. Also preferred is a library of compounds of formula (I) wherein R is a group —COR^(a) with R^(a) as a straight or branched C₁-C₆ alkyl, cycloalkyl or optionally substituted aryl or arylalkyl group.

Also preferred is a library of compounds of formula (I) wherein R is a group-CONR^(a)R^(b) with one of R^(a) and R^(b) as a hydrogen atom and the other of R^(a) and R^(b) as a straight or branched C₁-C₆ alkyl, optionally substituted aryl or arylalkyl group.

For a general reference to the above libraries of compounds of formula (I) see the experimental section.

From all of the above, it is clear to the skilled person that once a library of 3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one derivatives is thus prepared, for instance consisting of a few thousands of compounds of formula (I), the said library can be very advantageously used for screening towards given kinases, as formerly reported.

See, for a general reference to libraries of compounds and uses thereof as tools for screening biological activities, J. Med. Chem. 1999, 42, 2373-2382; and Bioorg. Med. Chem. Lett. 10 (2000), 223-226.

Pharmacology

The inhibiting activity of putative kinase inhibitors and the potency of selected compounds is determined through a method of assay based on the use of the Kinase-Glo® Luminescent Kinase Assay (commercially available from Promega corporation and described in Koresawa, M. and Okabe, T. (2004) High-throughput screening with quantitation of ATP consumption: A universal non-radioisotope, homogeneous assay for protein kinase. Assay Drug Dev. Technol. 2, 153-60).

The depletion of ATP as a result of kinase activity can be monitored in a highly sensitive manner through the use of Kinase-Glo® or Kinase-Glo® Plus Reagent, which uses luciferin, oxygen and ATP as substrates in a reaction that produces oxyluciferin and light.

The short forms and abbreviations used herein have the following meaning:

-   BSA bovine serum albumine -   Tris 2-Amino-2-(hydroxymethyl)-1,3-propanediol -   Hepes N-(2-Hydroxyethyl)piperazine-N′-(2-ethanesulfonic acid) -   DTT threo-1,4-Dimercapto-2,3-butanediol -   THF tetrahydrofurane -   MTBE methyl tertiary butyl ether -   DIPEA diisopropylethylamine -   PyBOP benzotriazol-1-yloxytris(pyrrolidino)phosphonium     exafluorophosphate -   TFA trifluoroacetic acid -   TMOF trimethyl orto formate -   DCE dichloroethane -   DCM dichloromethane -   DMF dimethylformammide -   DMSO dimethylsulfoxide -   KDa kiloDalton -   mg milligram -   μg microgram -   ng nanogram -   L liter -   mL milliliter -   μL microliter -   M molar -   mM millimolar -   μM micromolar -   nM nanomolar

Kinase reaction conditions are target (enzyme) dependent and thus undergo individual adaptations. The Kinase-Glo® Luminescent Kinase Assay can be used with virtually any kinase and substrate combination.

Also the buffer conditions may vary depending on the kinase of interest (e.g for PKA a composition of 40 mM Tris pH 7.5, 20 mM MgCl2, 0.1 mg/ml BSA, in 50 μl final volume is used). Typically the range of ATP titration is 0.1 μM to 10 μM.

The optimal kinase substrate results in the greatest change in luminescence when comparing kinase reaction wells with no kinase wells.

The optimal amount of kinase is determined by making two fold serial dilutions across plates using the optimal amount of ATP and optimal kinase substrate. The optimal amount of kinase to use in subsequent compound screens and IC50 determinations is the amount required for luminescence to be within the linear range of the kinase titration curve (sigmoidal dose response).

Robotized Kinase-Glo® Assay

This assay was set up for the measurement of kinase activity and/or inhibition. It is homogeneous, suitable for all type of protein kinases, quick and radioactivity-free.

We established the assay in 384 well-plates: the test mix consisted of:

-   1) 3× Enzyme mix (done in Kinase Buffer 3×), 5 μl well -   2) 3× substrate and ATP mix (done in ddH2O), 5 μl/well -   3) 3× compound of formula (I) (diluted into ddH2O—3% DMSO)—5     μl/well)

As an outcome, the percentage of inhibition at 10 μM was evaluated for each compound tested: see below for compound dilution and assay scheme. Each enzyme had its own buffer constitution, substrate type and concentration. Incubation time instead was 90 min for all targets.

Test compounds were received as a 1 mM solution in 100% DMSO into 96 well plates. The plates were diluted to 30 μM in ddH₂O, 3% DMSO; 4 plates are reorganized in 384 well plate by dispensing 5 μl of each 96wp into the four quadrants of a 384wp. In well P23 and P24 the internal standard inhibitor staurosporine was added.

Assay Scheme

Test plates were first added with 5 μl of the compound dilution (30 μM, corresponding to 3× dilution) and then loaded onto a robotized station together with one reservoir for the Enzyme mix (3×) and one for the ATP mix (3×), specific for each target under study.

To start the assay, the robot aspirated 5 μl of ATP/Substrate mix, made an air gap inside the tips (5 μl) and aspirated 5 μl of Enzyme mix. The subsequent dispensation into the test plates allowed the kinase reaction to start after 3 cycles of mixing, done by the robot itself by up and down pipetting. At this point, the correct concentration was restored for all reagents.

The robot incubated the plates for 90 minutes at room temperature, and then stopped the reaction by pipetting 15 μl of Kinase-Glo® reagent into the reaction mix. Three cycles of mixing were done immediately after the addition of the reagent.

The principle of the Kinase-Glo® technique is the presence in the reagent mixture of oxygen, luciferin and luciferase enzyme: in the presence of ATP, remaining from the kinase reaction, oxi-luciferin is produced with the emission of light, directly dependent on the amount of ATP. For optimal performances of this technique, the kinase reaction should utilize at least 15-20% of the available ATP.

After another 60 minutes of incubation to stabilize the luminescent signal, the plates were read on a ViewLux® instrument. Data were analyzed using the software package Assay Explorer® that provided percent inhibition data.

As example herein are reported the assay conditions used for testing the compounds of formula (I) against ALKtide YFF APCo kinase;

-   ATP concentration: 1 μM -   Enzyme concentration: 100 nM -   Reaction buffer: Hepes 50 mM pH 7.5, MgCl2 5 mM, MnCl2 1 mM, DTT 1     mM, NaOVO3 3 uM, 0.2 mg/ml BSA -   Assay procedure: add 5 ul compound of formula (I) (3×), add 5 μl     ATP/S mix(3×) in buffer 1×; add 5 μl enzyme in buffer 2×+3×BSA; for     the blank, add 5 μl buffer2×+3× BSA without enzyme. After 90 minutes     of incubation, add 15 μl/well of Kinase-Glo reagent. After 60-90     minutes of incubation to stabilize the luminescent signal, the     plates are read on a ViuwLux instrument.

Some representative compounds of the invention of formula (I), such as compound A23-M-B63, A23-M-B55 and A20-M-B14 (for the meanings of the codes, see the Examples section), at a dosage of 10 μM have been found to have a % inhibition >25% when tested in the method described above.

So far, the novel compounds of the invention are unexpectedly endowed with a kinase inhibitory activity against a selected panel of kinases, and are thus particularly advantageous, in therapy, against proliferative disorders associated with an altered kinase activity.

The compounds of the present invention can be administered either as single agents or, alternatively, in combination with known anticancer treatments such as radiation therapy or chemotherapy regimen in combination with cytostatic or cytotoxic agents, antibiotic-type agents, alkylating agents, antimetabolite agents, hormonal agents, immunological agents, interferon-type agents, cyclooxygenase inhibitors (e.g. COX-2 inhibitors), matrixmetalloprotease inhibitors, telomerase inhibitors, tyrosine kinase inhibitors, anti-growth factor receptor agents, anti-HER agents, anti-EGFR agents, anti-angiogenesis agents (e.g. angiogenesis inhibitors), farnesyl transferase inhibitors, ras-raf signal transduction pathway inhibitors, cell cycle inhibitors, other cdks inhibitors, tubulin binding agents, topoisomerase I inhibitors, topoisomerase II inhibitors, and the like.

If formulated as a fixed dose, such combination products employ the compounds of this invention within the dosage range described below and the other pharmaceutically active agent within the approved dosage range.

Compounds of formula (I) may be used sequentially with known anticancer agents when a combination formulation is inappropriate.

The compounds of formula (I) of the present invention, suitable for administration to a mammal, e.g., to humans, can be administered by the usual routes and the dosage level depends upon the age, weight, conditions of the patient and administration route.

For example, a suitable dosage adopted for oral administration of a compound of formula (I) may range from about 10 to about 500 mg per dose, from 1 to 5 times daily. The compounds of the invention can be administered in a variety of dosage forms, e.g., orally, in the form tablets, capsules, sugar or film coated tablets, liquid solutions or suspensions; rectally in the form suppositories; parenterally, e.g., intramuscularly, or through intravenous and/or intrathecal and/or intraspinal injection or infusion.

The present invention also includes pharmaceutical compositions comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof in association with a pharmaceutically acceptable excipient, which may be a carrier or a diluent.

The pharmaceutical compositions containing the compounds of the invention are usually prepared following conventional methods and are administered in a suitable pharmaceutical form. For example, the solid oral forms may contain, together with the active compound, diluents, e.g., lactose, dextrose saccharose, sucrose, cellulose, corn starch or potato starch; lubricants, e.g., silica, talc, stearic acid, magnesium or calcium stearate, and/or polyethylene glycols; binding agents, e.g., starches, arabic gum, gelatine methylcellulose, carboxymethylcellulose or polyvinyl pyrrolidone; disintegrating agents, e.g., starch, alginic acid, alginates or sodium starch glycolate; effervescing mixtures; dyestuffs; sweeteners; wetting agents such as lecithin, polysorbates, laurylsulphates; and, in general, non-toxic and pharmacologically inactive substances used in pharmaceutical formulations. These pharmaceutical preparations may be manufactured in known manner, for example, by means of mixing, granulating, tabletting, sugar-coating, or film-coating processes.

The liquid dispersions for oral administration may be, e.g., syrups, emulsions and suspensions. As an example, the syrups may contain, as carrier, saccharose or saccharose with glycerine and/or mannitol and sorbitol.

The suspensions and the emulsions may contain, as examples of carriers, natural gum, agar, sodium alginate, pectin, methylcellulose, carboxymethylcellulose, or polyvinyl alcohol. The suspension or solutions for intramuscular injections may contain, together with the active compound, a pharmaceutically acceptable carrier, e.g., sterile water, olive oil, ethyl oleate, glycols, e.g., propylene glycol and, if desired, a suitable amount of lidocaine hydrochloride.

The solutions for intravenous injections or infusions may contain, as a carrier, sterile water or preferably they may be in the form of sterile, aqueous, isotonic, saline solutions or they may contain propylene glycol as a carrier.

The suppositories may contain, together with the active compound, a pharmaceutically acceptable carrier, e.g., cocoa butter, polyethylene glycol, a polyoxyethylene sorbitan fatty acid ester surfactant or lecithin.

With the aim of better illustrating the present invention, without posing any limitation to it, the following examples are now given.

EXPERIMENTAL SECTION

General Methods

Flash Chromatography was performed on silica gel (Merck grade 9395, 60A). The high-pressure liquid chromatography retention times (HPLC: r.t. values) were determined by:

HPLC Method 1A and 1B:

A Waters Alliance LC mod. 2795 equipped with a variable UV detector mod 2487, a Chemiluminescence Nitrogen detector (CLND, Antek 8060) and a Waters ZQ2000 mass detector (ESI interface) was used in this application. The total flow was splitted and distributed to the three detectors at a fixed ratio (64:15:21 UV:MS:CLND). The liquid chromatograph was equipped with a 30×3.0 mm I.D. column (Waters) xBridge C18, 3.5 um particles), thermostated at 50° C. Two mobile phases were used: phase A was 0.05% w/v formic acid (1 mL/L of 50% formic acid Fluka 09676 in highly purified water) and phase B was 70/25/5 (v/v/v) MeOH/iPrOH/H2O containing 0.035% w/v of formic acid (700 uL/L of 50% formic acid Fluka 09676).

A 5 μL volume of 1 mM nominal sample solution in DMSO was injected (sequential, partial loop mode with no air gaps) and a generic reversed phase gradient analysis was carried out at 0.8 mL/min into either a fast variant (method 1A) or a slower one (method 1B), as indicated in the following table:

Method 1A Method 1B tR (min) phase B (%) tR (min) phase B (%) 0.00 0 0.00 0 5.00 100 8.00 100 5.70 100 9.00 100 5.71 0 9.01 0 6.3 stop time 9.6 stop time 7.9 total analysis time (*) 11.2 total analysis time (*) (*) between consecutive injections

The UV detector was operated at 220 nm, 5 Hz sampling rate. The MS device was operated at 3.2 kV capillary voltage, 30 V cone, 2 V extractor, 0.5 V RF lens, 400 L/hr desolvation flow, 100 L/hr cone flow, 100° C. source temperature, 150° C. desolvation temperature, ESI(+) full scan 120-1200 amu acquisition, at 1.7 Hz sampling rate. The CLND detector was operated at 1050° C. furnace temp, 280 mL/min inlet oxygen flow, 80 mL/min inlet argon, 25 mL/min make-up argon, 30 mL/min ozone, 28 ton vacuum, 750 V PMT voltage, PMT chamber at +10° C., sensitivity high, select 5, 4 Hz sampling rate.

HPLC Method 2:

Instrumentation: Waters 2790 HPLC system equipped with a 996 Waters PDA detector and Micromass mod. ZQ 2000 single quadrupole mass spectrometer, equipped with an electrospray (ESI) ion source.

Chromatographic condition: Waters X Terra RP18 (4,6×50 mm, 3.5 μm) column; Mobile phase A was ammonium acetate 5 mM buffer (pH 5.2 with acetic acid)/acetonitrile 95:5, and Mobile phase B was H₂O/acetonitrile (5:95). Gradient from 10 to 90% B in 8 minutes, hold 100% B for 2 minutes. PDA channels extracted at 220 nm and 254 nm. Flow rate 1 ml/min. Injection volume 10 μl. Full scan, mass range from 100 to 800 amu. Capillary voltage was 3.5 kV; source temp. was 120° C.; cone was 14 V. Retention times (HPLC r.t.) are given in minutes at 220 nm or at 254 nm. Mass is given as m/z ratio.

When necessary, the compounds have been purified by preparative HPLC on a Waters X-Bridge Prep Shield RP18 (19×100 mm, 5 μm) column or a Phenomenex Gemini C18 (21.2×250 mm, 10 μm) column, using a Waters FractionLynx Autopurification System equipped with a 996 Waters PDA detector and a Micromass mod. ZQ single quadrupole mass spectrometer, electron spray ionization, positive mode. Mobile phase A was water 0.05% NH3/acetonitrile 95:5, and Mobile phase B was acetonitrile. Gradient from 10 to 90% B in 8 min or 15 min Flow rate 20 ml/min.

¹H-NMR spectrometry was performed on a Bruker AVANCE 400 MHz single bay instrument with gradients. It is equipped with a QNP probe (interchangeable 4 nuclei probe—¹H, 13C, 19F and 31P) (NMR method 1) or on a Mercury VX 400 operating at 400.45 MHz equipped with a 5 mm double resonance probe [1H (15N-31P) ID_PFG Varian] (NMR method 2).

The compounds of formula (I), having an asymmetric carbon atom and obtained as racemic mixture, were resolved by HPLC separation on chiral columns. In particular, for example, preparative columns CHIRALPACK® AD, CHIRALPACK® AS, CHIRALCELL® OJ can be used.

As formerly indicated, several compounds of formula (I) of the invention have been synthesized in parallel, according to combinatorial chemistry techniques.

In this respect, some compounds thus prepared have been conveniently and unambiguously identified, as per the coding system of tables III, VI, V and VI together with HPLC retention time (methods 1 and 2) and mass.

Each code, which identifies a single specific compound of formula (I), consists of three units A-M-B.

A represents any substituent R₁— [see formula (I)] and is attached to the rest of the 3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one moiety through the carbon atom of the carbonyl group so as to get 3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one derivatives; each A radical (substituent) is represented in the following table I.

B represents any substituent R—[see formula (I)] and is attached to the rest of the 3,4-dihydro-2H-pyrazino [1,2-a]indol-1-one moiety through the nitrogen atom of the NH group so as to get 3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one derivatives being substituted in position 8; each B radical (substituent) is represented in the following table II.

M refers to the central core of the divalent 3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one moiety being substituted at the carbonyl group by groups A and in position 8 (through the NH group) by groups B, substantially as follows:

For ease of reference, each A or B groups of tables I and II has been identified with the proper chemical formula also indicating the point of attachment with the rest of the molecule M.

Just as an example, the compound A2-M-B2 of table III (entry 1) represents an 3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one M being substituted in position 8 by the group B2 (through the NH group), and by the group A2 through the CO group; likewise, the compound A4-M-09 of table IV (entry 780) represents an 3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one M being substituted in position by the group B9 (through the NH group), and by the group A4 through the CO group, as follows:

TABLE I A groups Fragment CODE

A1 

A2 

A3 

A4 

A5 

A6 

A7 

A8 

A9 

A10

A11

A12

A13

A14

A15

A16

A17

A18

A19

A20

A21

A22

A23

A24

A25

A26

A27

A28

TABLE II B groups Fragment CODE

B1 

B2 

B3 

B4 

B5 

B6 

B7 

B8 

B9 

B10

B11

B12

B13

B14

B15

B16

B17

B18

B19

B20

B21

B22

B23

B24

B25

B26

B27

B28

B29

B30

B31

B32

B33

B34

B35

B36

B37

B38

B39

B40

B41

B42

B43

B44

B45

B46

B47

B48

B49

B50

B51

B52

B53

B54

B55

B56

B57

B58

B59

B60

B61

B62

B63

B64

B65

B66

B67

B68

B69

B70

B71

B72

B73

B74

B75

B76

Preparation of 5-nitro-1H-indole-2-carboxylic acid (III)

LiOH.H2O (1.06 g, 46.2 mmol, 2.1 eq.) was added to a suspension of 5-nitro-1H-indole-2-carboxylic acid ethyl ester (II) (5.15 g, 22 mmol, 1 eq.) in THF/MeOH/H2O 1:1:2 (180 ml). The final suspension turned to dark yellow and was stirred at 25° C. After 30 min the solubilization was complete and total conversion was achieved after 6 hours. The reaction mixture was cooled to 0° C. and quenched with HCl 2N until the solution reached pH 5. Organic volatiles were removed under reduced pressure and the white precipitate was filtered and dried to give the compound of formula (III). Yield=4.53 g (quantitative). Same procedure on 50 g scale afforded 42.2 g of the compound of formula (III) (96% yield).

LCMS (HPLC Method 2): m/z 205 [M−H]⁻ @ r.t. 2.58 min ¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.59 (dd, J=15.91, 5.67 Hz, 1 H) 2.82 (dd, J=15.97, 8.29 Hz, 1 H) 3.58 (dd, J=12.86, 5.67 Hz, 1 H) 3.89 (dd, J=13.35, 4.08 Hz, 1 H) 5.17-5.23 (m, 1 H) 7.36 (s, 1 H) 7.80 (d, J=9.15 Hz, 1 H) 8.15 (dd, J=9.15, 2.32 Hz, 1 H) 8.27 (d, J=5.12 Hz, 1 H) 8.72 (d, J=2.32 Hz, 1 H) 12.58 (br. s., 1 H).

Preparation of 5-nitro-1H-indole-2-carboxylic acid (2,2-dimethoxy-ethyl)-amide (IV)

Thionyl chloride (8 ml, 110 mmol, 5 eq.) was added to a suspension of the compound of formula (III) (4.53 g, 22 mmol, 1 eq.) in dry dioxane (50 ml). The final suspension was refluxed in dry atmosphere (CaCl2 valve) for 2 h, and the reaction turned to a light brown solution while proceeding. The reaction was cooled to 25° C. and organic volatiles were removed under reduced pressure, then dry toluene (25 ml) was added and removed under vacuum, this operation was repeated twice. The brown residue (22 mmol, 1 eq.) was added portion wise to a cooled solution at 0° C. of NaHCO₃ (3.7 g, 43.95 mmol, 2 eq.) and 2,2-dimethoxy-ethylamine (2.39 ml, 21.97 mmol, 1 eq.) in dioxane/water 4:1 (100 ml), the suspension was stirred for 2 hours at rt. Organic volatiles were removed under reduced pressure and the yellow precipitate was filtered and dried to give 5-nitro-1H-indole-2-carboxylic acid (2,2-dimethoxy-ethyl)-amide (IV). Yield=5.80 g (90%).

Same procedure on 42.2 g scale afforded 52.75 g of a compound of formula (IV)(82% yield).

LCMS (HPLC Method 2): m/z 294 [M+H]⁺ @ r.t. 4.46 min. ¹H NMR (400 MHz, DMSO-d₆) δ ppm 3.31 (s, 6 H) 3.40 (t, J=5.73 Hz, 2 H) 4.53 (t, J=5.49 Hz, 1 H) 7.43 (d, J=1.46 Hz, 1 H) 7.57 (d, J=9.02 Hz, 1 H) 8.07 (dd, J=9.02, 2.32 Hz, 1 H) 8.70 (d, J=2.32 Hz, 1 H) 8.80 (t, J=6.04 Hz, 1 H) 12.30 (s, 1 H).

Preparation of 4-hydroxy-8-nitro-3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one (V)

HCl 2N (13.75 ml, 27.5 mmol, 2.5 eq.) was added to a solution of the compound of formula (IV) (3 g, 11 mmol, 1 eq.) in acetone (200 ml), the final solution was stirred at 25° C. for 48 h. The solution was dried under reduced pressure affording the compound of formula (V) as yellow solid that was used in the subsequent step without further purification. Same procedure on 30 g scale proceeded smoothly. Typical yield: 97%.

Warning: on higher scale a careful drying step until constant weight is mandatory in order to avoid that residual HCl interferes in the following step.

LCMS (HPLC Method 2): m/z 246 [M−H]⁻ @ r.t. 3.1 min (broad peak).

Preparation of (8-nitro-1-oxo-1,2,3,4-tetrahydro-pyrazino[1,2-a]indol-4-yl)-acetic acid methyl ester (VII)

LiOH*H₂O (509 mg, 12.14 mmol, 1.5 eq.) was added to a solution of trimethyl phosphono acetate (VI) (1.28 ml, 8.90 mmol, 1.2 eq.), to the compound of formula (V) (2.0 g, 8.09 mmol, 1 eq.) and water (4.4 ml, 240 mmol, 30 eq.) in THF (100 ml) and the solution was stirred at 25° C. for 4 hours, then organic volatiles were removed under reduced pressure and the crude residue was used in the next step without further purification, after addition of 100 ml of water.

On higher scale (110 mol) the reaction was worse (low conversion) for the mentioned above residue of HCl.

LCMS (HPLC Method 2): m/z 304 [M+H]⁺ @ r.t. 3.96 min. ¹H NMR (on isolated product) (400 MHz, DMSO-d6) δ ppm 2.68 (dd, J=15.61, 6.22 Hz, 1 H) 2.92 (dd, J=15.49, 7.44 Hz, 1 H) 3.51 (s, 3 H) 3.58 (ddd, J=13.29, 5.37, 1.10 Hz, 1 H) 3.90 (dd, J=13.41, 4.15 Hz, 1 H) 5.25 (dt, J=6.83, 3.66 Hz, 1 H) 7.36 (s, 1 H) 7.75 (d, J=9.15 Hz, 1 H) 8.17 (dd, J=9.27, 2.32 Hz, 1 H) 8.28 (d, J=5.00 Hz, 1 H) 8.72 (d, J=2.20 Hz, 1 H).

Preparation of (8-nitro-1-oxo-1,2,3,4-tetrahydro-pyrazino[1,2-a]indol-4-yl)-acetic acid (VII)

LiOH*H₂O (408 mg, 9.72 mmol, 1.2 eq.) was added to aqueous solution of the crude of example 4 and the resultant suspension was stirred at 25° C. for 4 hours. The brown suspension was filtered. The dark brown mother solution was quenched with HCl 2N until pH 5 was reached (yellow precipitate), organic volatiles were removed under reduced pressure and the yellow precipitate was filtered. The crude material was stirred with acetone (20 ml/g of crude) for 12 hours then the undissolved material was filtered and dried under reduced pressure (light yellow solid). Yields: 1.2 g of the acid derivative of formula (VII) (50% over two steps) 89% UV purity @254 nm.

Same procedure on higher scale afforded the compound of formula III with average yields of 35% over two steps and 90% UV purity @254 nm, the main impurity is the starting material of example 4.

LCMS (HPLC Method 2): m/z 288 [M−H]⁻ @ r.t. 2.62 min. ¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.59 (dd, J=15.91, 5.67 Hz, 1 H) 2.82 (dd, J=15.97, 8.29 Hz, 1 H) 3.58 (dd, J=12.86, 5.67 Hz, 1 H) 3.89 (dd, J=13.35, 4.08 Hz, 1 H) 5.17-5.23 (m, 1 H) 7.36 (s, 1 H) 7.80 (d, J=9.15 Hz, 1 H) 8.15 (dd, J=9.15, 2.32 Hz, 1 H) 8.27 (d, J=5.12 Hz, 1 H) 8.72 (d, J=2.32 Hz, 1 H) 12.58 (br. s., 1 H).

General Procedure: Loading of Allylamine (Corresponding to Fragment A7 of Table I) onto Acid Sensitive Methoxy Benzaldehyde Polystyrene Resin (AMEBA II Resin).

4-(4-formyl-3-methoxyphenoxy)butyryl aminomethyl resin (copolystyrene-1% DVB) (6.0 g, 5.88 mmol, 0.98 mmol/g, 1 eq.) was suspended in dry THF (60 ml) and allylamine (29.4 mmol, 5 eq.) was added. The resultant suspension was shaken at 25° C. for 2 h. Then acetic acid (1.68 ml, 29.4 mmol, 5 eq.) and NaBH(AcO)₃ (3.12 g, 14.7 mmol, 3 eq.) were added and the final suspension was shaken for 16 h at 25° C. The resin was rinsed with THF (2 cycles), MeOH (2 cycles), DCM (2 cycles), MeOH (2 cycles), DMF (2 cycles) and DCM (3 cycles) then dried in nitrogen flux.

Loading of the 3,4-dihydro-2h-pyrazino[1,2-a]indol-1-one scaffold onto the resin prepared above

A solution of the acid derivative of formula (VII) (57 mg, 0.2 mmol, 2 eq), DIPEA (0.068 ml, 0.39 mmol, 4 eq.), PyBOP (102.75 mg, 0.2 mmol, 2 eq.) in dry DMA (2.0 ml) was stirred for 30 min then was added to resin of example 6 (0.1 mmol, 1 eq.) and the final suspension was shaken for 20 h at 25° C. The resin was washed sequentially with DMF (1 ml), DCM (1 ml), DMF (1 ml), DCM (1 ml), MeOH (1 ml), water (1 ml), MeOH (1 ml), DCM (1 ml), MeOH (1 ml), DCM (1 ml), MeOH (1 ml), MTBE (1 ml, 2 cycles) and then air dried.

Reduction of the Nitro Group

The resin of formula (XVIII) (0.1 mmol, 1 eq.) was suspended in a 2M solution of SnCl₂*2H₂O in DMF (1.5 ml). The final compound of formula (XIX) in suspension was shaken for 48 hours at 25° C. The resin was washed sequentially with DMF (1 ml), DCM (1 ml), DMF (1 ml), DCM (1 ml), MeOH (1 ml), water (1 ml), MeOH (1 ml), DCM (1 ml), MeOH (1 ml), DCM (1 ml), MeOH (1 ml), MTBE (1 ml, 2 cycles) and then dried in nitrogen flux. The above resin bound 3,4-dihydro-2h-pyrazino[1,2-a]indol-1-one was further reacted according to the alternative steps below so as to get carboxamido, sulfonamido, ureido and amino derivatives.

Example 1

Preparation of A28-M-B1

A carboxylic acid of formula (VIII), wherein R^(a) corresponds to the fragment B1 of table II, (0.3 mmol, 3 eq.), was added to a the resin of example 8 wherein R^(c) corresponds to the fragment A28 of table I, in solution of DIPEA (68.5 μl, 0.4 mmol, 4 eq.) and PyBOP (156 mg, 0.3 mmol, 3 eq.) in dry DMF (2.5 ml) and the solution was stirred for 30 min then was added to the resin of example 8 (0.1 mmol, 1 eq.) and shaken at 25° C. in a reactor (Quest 210™ or Miniblocks™). The resin was washed sequentially with DMF (1 ml), DCM (1 ml), DMF (1 ml), DCM (1 ml), MeOH (1 ml), water (1 ml), MeOH (1 ml), DCM (1 ml), MeOH (1 ml), DCM (1 ml), MeOH (1 ml), MTBE (1 ml, 2 cycles) and then air dried. The Resin (0.1 mmol, 1 eq.) was suspended in a solution of TFA/DCM 1:1 (2 ml) and shaken for 2 h at 25° C. The solution phase was collected and the resin was rinsed with DCM (collected as well), and a second cycle was performed. The final washing was performed with MeOH. All the collected were dried under reduced pressure affording compound A28-M-B1 (see entry 754 of table III below).

LCMS (HPLC Method 1A): m/z 377 [M+H]⁺ @ r.t. 2.41 min. ¹H NMR (400 MHz, DMSO-d₆) δ ppm 9.62 (s, 1H), 8.07 (s, 1H), 8.03 (d, J=4.9 Hz, 1H), 7.92 (t, J=5.6 Hz, 1H), 7.36-7.47 (m, 2H), 7.00 (s, 1H), 4.85-5.14 (m, 1H), 3.83 (dd, J=13.2, 4.3 Hz, 1H), 3.48 (dd, J=12.8, 5.6 Hz, 1H), 3.09 (s, 2H), 2.85-3.03 (m, 2H), 2.31 (s, 6H), 2.20 (br. s., 8H), 1.27-1.51 (m, 2H).

Following the procedure described in example 9 and by using any proper reactant as per the process of the invention that is, by supporting any suitable amine onto the resin, by acylating the amino function in position 8 of the 3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one moiety with any suitable carboxylic acid derivative and by finally carrying out resin cleavage, the following compounds of table III were also prepared.

TABLE III HPLC HPLC Entry Compound Method tR (min) [M + H]+ 1 A2-M-B2 1B 0.49 429 2 A2-M-B3 1B 3.02 468 3 A2-M-B4 1B 3.09 506 4 A3-M-B2 1B 0.49 457 5 A3-M-B12 1B 3.15 519 6 A3-M-B4 1B 3.16 534 7 A4-M-B2 1B 0.53 402 8 A4-M-B3 1B 4.31 441 9 A4-M-B12 1B 4.26 464 10 A4-M-B4 1B 4.36 479 11 A5-M-B2 1B 2.47 448 12 A5-M-B3 1B 5.38 487 13 A5-M-B12 1B 5.35 510 14 A5-M-B4 1B 5.39 525 15 A6-M-B2 1B 2.37 414 16 A6-M-B3 1B 5.35 453 17 A6-M-B12 1B 5.33 476 18 A6-M-B4 1B 5.36 491 19 A7-M-B2 1B 0.55 384 20 A7-M-B3 1B 4.54 423 21 A7-M-B12 1B 4.48 446 22 A7-M-B4 1B 4.57 461 23 A8-M-B4 1B 3.15 506 24 A10-M-B14 1A 2.58 472 25 A10-M-B15 1A 2.49 425 26 A10-M-B16 1A 2.24 411 27 A10-M-B17 1A 3.22 475 28 A10-M-B18 1A 2.7 465 29 A10-M-B20 1A 2.55 453 30 A10-M-B22 1A 2.77 461 31 A10-M-B23 1A 2.98 461 32 A10-M-B24 1A 2.98 461 33 A10-M-B25 1A 3.06 453 34 A10-M-B26 1A 2.82 441 35 A10-M-B27 1A 2.63 427 36 A10-M-B28 1A 3.11 475 37 A10-M-B29 1A 2.57 472 38 A10-M-B30 1A 2.66 499 39 A10-M-B31 1A 2.54 483 40 A10-M-B33 1A 2.58 427 41 A10-M-B34 1A 3.1 483 42 A10-M-B35 1A 3.33 467 43 A10-M-B36 1A 2.76 439 44 A10-M-B37 1A 2.55 453 45 A10-M-B38 1A 2.74 467 46 A10-M-B39 1A 3.1 483 47 A10-M-B40 1A 3.11 475 48 A10-M-B41 1A 2.91 499 49 A10-M-B42 1A 2.83 499 50 A11-M-B33 1A 2.68 385 51 A10-M-B43 1A 2.59 427 52 A10-M-B44 1A 2.22 441 53 A10-M-B45 1A 2.26 498 54 A10-M-B46 1A 2.71 481 55 A10-M-B47 1A 2.1 399 56 A10-M-B48 1A 2.71 427 57 A10-M-B49 1A 2.36 413 58 A10-M-B50 1A 2.33 413 59 A10-M-B51 1A 2.85 465 60 A10-M-B52 1A 1.88 385 61 A10-M-B54 1A 2.86 465 62 A10-M-B59 1A 3.19 479 63 A10-M-B60 1A 2.47 465 64 A10-M-B61 1A 2.44 465 65 A12-M-B14 1A 2.46 513 66 A12-M-B15 1A 2.37 466 67 A12-M-B16 1A 2.14 452 68 A12-M-B17 1A 3.08 516 69 A12-M-B64 1A 1.96 489 70 A12-M-B20 1A 2.43 494 71 A12-M-B22 1A 2.63 502 72 A11-M-B34 1A 3.22 441 73 A12-M-B24 1A 2.83 502 74 A12-M-B25 1A 2.88 494 75 A12-M-B26 1A 2.67 482 76 A11-M-B35 1A 3.46 425 77 A12-M-B28 1A 2.96 516 78 A11-M-B36 1A 2.87 397 79 A12-M-B30 1A 2.54 540 80 A12-M-B31 1A 2.41 524 81 A12-M-B33 1A 2.45 468 82 A12-M-B65 1A 2.72 524 83 A12-M-B34 1A 2.96 524 84 A12-M-B35 1A 3.19 508 85 A12-M-B36 1A 2.62 480 86 A12-M-B66 1A 3.16 516 87 A12-M-B37 1A 2.43 494 88 A12-M-B38 1A 2.61 508 89 A12-M-B39 1A 2.95 524 90 A12-M-B40 1A 2.96 516 91 A12-M-B41 1A 2.76 540 92 A12-M-B43 1A 2.46 468 93 A12-M-B46 1A 2.57 523 94 A12-M-B47 1A 2 440 95 A12-M-B48 1A 2.57 468 96 A12-M-B49 1A 2.25 454 97 A12-M-B50 1A 2.2 454 98 A12-M-B51 1A 2.71 506 99 A13-M-B14 1A 2.62 430 100 A13-M-B15 1A 2.54 383 101 A13-M-B16 1A 2.28 369 102 A13-M-B17 1A 3.31 433 103 A13-M-B18 1A 2.77 423 104 A13-M-B64 1A 2.06 406 105 A13-M-B20 1A 2.6 411 106 A13-M-B22 1A 2.85 419 107 A13-M-B23 1A 3.06 419 108 A13-M-B24 1A 3.04 419 109 A13-M-B25 1A 3.12 411 110 A13-M-B26 1A 2.89 399 111 A13-M-B27 1A 2.7 385 112 A13-M-B28 1A 3.19 433 113 A13-M-B29 1A 2.62 430 114 A13-M-B30 1A 2.72 457 115 A13-M-B31 1A 2.58 441 116 A13-M-B33 1A 2.63 385 117 A13-M-B34 1A 3.19 441 118 A13-M-B35 1A 3.43 425 119 A13-M-B36 1A 2.83 397 120 A13-M-B66 1A 3.39 433 121 A13-M-B37 1A 2.61 411 122 A13-M-B38 1A 2.81 425 123 A13-M-B39 1A 3.16 441 124 A13-M-B40 1A 3.19 433 125 A13-M-B41 1A 2.98 457 126 A13-M-B42 1A 2.88 457 127 A13-M-B67 1A 3.22 457 128 A13-M-B43 1A 2.63 385 129 A13-M-B44 1A 2.24 399 130 A13-M-B45 1A 2.3 456 131 A13-M-B46 1A 2.77 439 132 A13-M-B47 1A 2.12 357 133 A13-M-B48 1A 2.78 385 134 A13-M-B49 1A 2.4 371 135 A13-M-B50 1A 2.37 371 136 A13-M-B51 1A 2.91 423 137 A13-M-B54 1A 2.92 423 138 A13-M-B59 1A 3.26 437 139 A13-M-B68 1A 2.31 409 140 A13-M-B60 1A 2.52 423 141 A13-M-B61 1A 2.5 423 142 A14-M-B14 1A 3 478 143 A14-M-B15 1A 2.96 431 144 A14-M-B16 1A 2.69 417 145 A14-M-B17 1A 3.62 481 146 A14-M-B18 1A 3.14 471 147 A14-M-B20 1A 2.99 459 148 A14-M-B22 1A 3.22 467 149 A14-M-B23 1A 3.41 467 150 A14-M-B24 1A 3.39 467 151 A14-M-B25 1A 3.48 459 152 A14-M-B26 1A 3.28 447 153 A14-M-B28 1A 3.53 481 154 A14-M-B29 1A 2.99 478 155 A14-M-B30 1A 3.09 505 156 A14-M-B31 1A 2.95 489 157 A14-M-B33 1A 3.05 433 158 A14-M-B34 1A 3.55 489 159 A14-M-B35 1A 3.73 473 160 A14-M-B66 1A 3.7 481 161 A14-M-B37 1A 3.01 459 162 A14-M-B38 1A 3.18 473 163 A14-M-B39 1A 3.52 489 164 A14-M-B40 1A 3.52 481 165 A14-M-B41 1A 3.35 505 166 A14-M-B42 1A 3.26 505 167 A14-M-B67 1A 3.55 505 168 A14-M-B44 1A 2.65 447 169 A14-M-B45 1A 2.68 504 170 A14-M-B52 1A 2.28 391 171 A14-M-B54 1A 3.3 471 172 A14-M-B59 1A 3.58 485 173 A15-M-B14 1A 2.83 444 174 A15-M-B15 1A 2.78 397 175 A15-M-B16 1A 2.51 383 176 A15-M-B17 1A 3.5 447 177 A15-M-B18 1A 2.99 437 178 A15-M-B20 1A 2.82 425 179 A15-M-B22 1A 3.06 433 180 A15-M-B23 1A 3.26 433 181 A15-M-B24 1A 3.25 433 182 A15-M-B25 1A 3.33 425 183 A15-M-B26 1A 3.13 413 184 A11-M-B66 1A 3.43 433 185 A15-M-B29 1A 2.83 444 186 A15-M-B30 1A 2.93 471 187 A15-M-B31 1A 2.8 455 188 A15-M-B33 1A 2.87 399 189 A15-M-B34 1A 3.4 455 190 A15-M-B35 1A 3.62 439 191 A11-M-B37 1A 2.64 411 192 A15-M-B37 1A 2.84 425 193 A15-M-B38 1A 3.02 439 194 A15-M-B39 1A 3.37 455 195 A15-M-B40 1A 3.38 447 196 A15-M-B41 1A 3.2 471 197 A15-M-B42 1A 3.1 471 198 A15-M-B67 1A 3.41 471 199 A15-M-B44 1A 2.45 413 200 A15-M-B45 1A 2.5 470 201 A15-M-B52 1A 2.09 357 202 A15-M-B54 1A 3.14 437 203 A15-M-B59 1A 3.46 451 204 A16-M-B14 1A 2.91 456 205 A16-M-B15 1A 2.87 409 206 A16-M-B16 1A 2.6 395 207 A16-M-B17 1A 3.57 459 208 A16-M-B18 1A 3.07 449 209 A16-M-B64 1A 2.33 432 210 A16-M-B20 1A 2.91 437 211 A16-M-B22 1A 3.15 445 212 A16-M-B23 1A 3.35 445 213 A16-M-B24 1A 3.33 445 214 A16-M-B25 1A 3.42 437 215 A16-M-B26 1A 3.21 425 216 A16-M-B27 1A 3.03 411 217 A16-M-B28 1A 3.45 459 218 A16-M-B29 1A 2.91 456 219 A16-M-B30 1A 3.01 483 220 A16-M-B31 1A 2.87 467 221 A16-M-B33 1A 2.97 411 222 A16-M-B34 1A 3.49 467 223 A16-M-B35 1A 3.69 451 224 A16-M-B36 1A 3.14 423 225 A16-M-B66 1A 3.64 459 226 A16-M-B37 1A 2.93 437 227 A16-M-B38 1A 3.11 451 228 A16-M-B39 1A 3.47 467 229 A16-M-B40 1A 3.47 459 230 A16-M-B41 1A 3.28 483 231 A16-M-B42 1A 3.18 483 232 A16-M-B67 1A 3.49 483 233 A16-M-B43 1A 2.98 411 234 A16-M-B44 1A 2.54 425 235 A16-M-B45 1A 2.59 482 236 A16-M-B46 1A 3.07 465 237 A16-M-B47 1A 2.42 383 238 A16-M-B48 1A 3.09 411 239 A16-M-B49 1A 2.74 397 240 A16-M-B50 1A 2.7 397 241 A16-M-B51 1A 3.22 449 242 A16-M-B52 1A 2.16 369 243 A16-M-B54 1A 3.22 449 244 A16-M-B59 1A 3.53 463 245 A11-M-B38 1A 2.84 425 246 A16-M-B61 1A 2.78 449 247 A17-M-B14 1A 2.74 468 248 A17-M-B17 1A 3.39 471 249 A11-M-B39 1A 3.21 441 250 A18-M-B14 1A 3.15 492 251 A18-M-B15 1A 3.14 445 252 A18-M-B16 1A 2.88 431 253 A18-M-B17 1A 3.73 495 254 A18-M-B18 1A 3.28 485 255 A18-M-B20 1A 3.15 473 256 A18-M-B22 1A 3.35 481 257 A18-M-B23 1A 3.55 481 258 A18-M-B25 1A 3.62 473 259 A18-M-B26 1A 3.44 461 260 A11-M-B40 1A 3.21 433 261 A11-M-B41 1A 3.02 457 262 A18-M-B30 1A 3.24 519 263 A11-M-B42 1A 2.91 457 264 A18-M-B33 1A 3.23 447 265 A18-M-B34 1A 3.68 503 266 A18-M-B35 1A 3.85 487 267 A18-M-B66 1A 3.81 495 268 A18-M-B37 1A 3.17 473 269 A18-M-B38 1A 3.31 487 270 A18-M-B39 1A 3.65 503 271 A11-M-B67 1A 3.24 457 272 A18-M-B41 1A 3.47 519 273 A18-M-B42 1A 3.4 519 274 A18-M-B67 1A 3.66 519 275 A11-M-B43 1A 2.68 385 276 A18-M-B45 1A 2.86 518 277 A18-M-B52 1A 2.49 405 278 A18-M-B54 1A 3.45 485 279 A18-M-B59 1A 3.71 499 280 A4-M-B15 1A 2.33 399 281 A4-M-B16 1A 2.1 385 282 A4-M-B17 1A 3.09 449 283 A4-M-B18 1A 2.57 439 284 A4-M-B64 1A 1.9 422 285 A4-M-B20 1A 2.39 427 286 A4-M-B22 1A 2.63 435 287 A4-M-B23 1A 2.86 435 288 A4-M-B24 1A 2.83 435 289 A4-M-B25 1A 2.89 427 290 A4-M-B26 1A 2.65 415 291 A4-M-B27 1A 2.48 401 292 A4-M-B28 1A 2.96 449 293 A4-M-B29 1A 2.43 446 294 A4-M-B30 1A 2.52 473 295 A4-M-B31 1A 2.4 457 296 A4-M-B33 1A 2.42 401 297 A4-M-B34 1A 2.96 457 298 A4-M-B35 1A 3.21 441 299 A4-M-B36 1A 2.61 413 300 A11-M-B44 1A 2.28 399 301 A4-M-B37 1A 2.4 427 302 A4-M-B38 1A 2.6 441 303 A4-M-B39 1A 2.93 457 304 A4-M-B40 1A 2.97 449 305 A4-M-B41 1A 2.76 473 306 A4-M-B42 1A 2.67 473 307 A4-M-B67 1A 3 473 308 A4-M-B43 1A 2.43 401 309 A4-M-B44 1A 2.08 415 310 A4-M-B46 1A 2.56 455 311 A4-M-B47 1A 1.96 373 312 A4-M-B48 1A 2.56 401 313 A4-M-B49 1A 2.21 387 314 A4-M-B50 1A 2.17 387 315 A4-M-B51 1A 2.69 439 316 A4-M-B54 1A 2.7 439 317 A4-M-B59 1A 3.06 453 318 A4-M-B60 1A 2.34 439 319 A4-M-B61 1A 2.33 439 320 A19-M-B17 1A 3.15 419 321 A19-M-B64 1A 1.91 392 322 A19-M-B25 1A 2.95 397 323 A19-M-B26 1A 2.7 385 324 A19-M-B28 1A 3.01 419 325 A19-M-B29 1A 2.46 416 326 A19-M-B30 1A 2.55 443 327 A19-M-B31 1A 2.42 427 328 A19-M-B33 1A 2.46 371 329 A19-M-B65 1A 2.78 427 330 A19-M-B34 1A 3.01 427 331 A19-M-B35 1A 3.28 411 332 A19-M-B66 1A 3.24 419 333 A19-M-B37 1A 2.42 397 334 A19-M-B38 1A 2.64 411 335 A11-M-B45 1A 2.32 456 336 A19-M-B40 1A 3.01 419 337 A19-M-B41 1A 2.81 443 338 A19-M-B42 1A 2.71 443 339 A19-M-B67 1A 3.05 443 340 A11-M-B46 1A 2.8 439 341 A19-M-B45 1A 2.14 442 342 A19-M-B52 1A 1.76 329 343 A19-M-B54 1A 2.74 409 344 A19-M-B59 1A 3.09 423 345 A19-M-B68 1A 2.17 395 346 A19-M-B61 1A 2.36 409 347 A20-M-B14 1A 3.39 484 348 A20-M-B15 1A 3.4 437 349 A20-M-B16 1A 3.23 423 350 A20-M-B17 1A 4 487 351 A20-M-B18 1A 3.58 477 352 A20-M-B64 1A 2.87 460 353 A20-M-B20 1A 3.46 465 354 A20-M-B22 1A 3.67 473 355 A20-M-B23 1A 3.83 473 356 A20-M-B24 1A 3.81 473 357 A11-M-B47 1A 2.15 357 358 A20-M-B26 1A 3.73 453 359 A20-M-B28 1A 3.93 487 360 A20-M-B29 1A 3.44 484 361 A20-M-B30 1A 3.51 511 362 A20-M-B31 1A 3.4 495 363 A20-M-B33 1A 3.56 439 364 A20-M-B36 1A 3.7 451 365 A20-M-B66 1A 4.07 487 366 A20-M-B37 1A 3.49 465 367 A20-M-B39 1A 3.93 495 368 A20-M-B40 1A 3.93 487 369 A20-M-B42 1A 3.68 511 370 A20-M-B67 1A 3.92 511 371 A20-M-B43 1A 3.53 439 372 A20-M-B44 1A 3.14 453 373 A20-M-B45 1A 3.17 510 374 A20-M-B46 1A 3.58 494 375 A20-M-B47 1A 3.09 411 376 A20-M-B49 1A 3.28 425 377 A20-M-B52 1A 2.75 397 378 A20-M-B54 1A 3.73 477 379 A20-M-B59 1A 3.95 491 380 A20-M-B60 1A 3.33 477 381 A7-M-B17 1A 3.25 431 382 A7-M-B64 1A 1.99 404 383 A7-M-B25 1A 3.06 409 384 A7-M-B26 1A 2.84 397 385 A7-M-B28 1A 3.13 431 386 A7-M-B29 1A 2.56 428 387 A7-M-B30 1A 2.67 455 388 A7-M-B31 1A 2.52 439 389 A7-M-B33 1A 2.58 383 390 A7-M-B65 1A 2.88 439 391 A7-M-B34 1A 3.13 439 392 A7-M-B35 1A 3.38 423 393 A7-M-B66 1A 3.35 431 394 A7-M-B37 1A 2.55 409 395 A7-M-B38 1A 2.75 423 396 A7-M-B39 1A 3.11 439 397 A7-M-B40 1A 3.13 431 398 A7-M-B41 1A 2.92 455 399 A7-M-B42 1A 2.83 455 400 A7-M-B67 1A 3.15 455 401 A7-M-B44 1A 2.19 397 402 A7-M-B45 1A 2.26 454 403 A7-M-B52 1A 1.85 341 404 A7-M-B1 1A 2.65 403 405 A7-M-B54 1A 2.86 421 406 A7-M-B59 1A 3.2 435 407 A11-M-B48 1A 2.82 385 408 A21-M-B14 1A 3.07 496 409 A21-M-B15 1A 3.07 449 410 A21-M-B16 1A 2.8 435 411 A21-M-B17 1A 3.7 499 412 A21-M-B18 1A 3.22 489 413 A21-M-B64 1A 2.51 472 414 A21-M-B20 1A 3.07 477 415 A21-M-B22 1A 3.32 485 416 A21-M-B23 1A 3.5 485 417 A21-M-B24 1A 3.47 485 418 A21-M-B25 1A 3.58 477 419 A21-M-B26 1A 3.39 465 420 A21-M-B27 1A 3.22 451 421 A21-M-B28 1A 3.61 499 422 A21-M-B29 1A 3.05 496 423 A21-M-B30 1A 3.16 523 424 A21-M-B31 1A 3.02 507 425 A21-M-B33 1A 3.17 451 426 A21-M-B34 1A 3.62 507 427 A21-M-B35 1A 3.8 491 428 A21-M-B36 1A 3.34 463 429 A21-M-B66 1A 3.76 499 430 A21-M-B37 1A 3.1 477 431 A21-M-B38 1A 3.28 491 432 A21-M-B39 1A 3.59 507 433 A21-M-B40 1A 3.61 499 434 A21-M-B41 1A 3.43 523 435 A21-M-B42 1A 3.33 523 436 A21-M-B67 1A 3.61 523 437 A21-M-B43 1A 3.21 451 438 A21-M-B44 1A 2.76 465 439 A21-M-B45 1A 2.73 522 440 A21-M-B46 1A 3.23 505 441 A21-M-B47 1A 2.64 423 442 A21-M-B48 1A 3.27 451 443 A21-M-B49 1A 2.93 437 444 A21-M-B50 1A 2.92 437 445 A21-M-B52 1A 2.37 409 446 A21-M-B54 1A 3.37 489 447 A21-M-B59 1A 3.64 503 448 A21-M-B68 1A 2.75 475 449 A21-M-B60 1A 2.96 489 450 A21-M-B61 1A 2.93 489 451 A22-M-B14 1A 2.48 428 452 A22-M-B15 1A 2.37 381 453 A22-M-B16 1A 2.13 367 454 A22-M-B17 1A 3.15 431 455 A22-M-B18 1A 2.62 421 456 A11-M-B49 1A 2.44 371 457 A22-M-B20 1A 2.43 409 458 A22-M-B22 1A 2.67 417 459 A22-M-B23 1A 2.91 417 460 A22-M-B24 1A 2.88 417 461 A22-M-B25 1A 2.96 409 462 A22-M-B26 1A 2.71 397 463 A22-M-B27 1A 2.54 383 464 A22-M-B28 1A 3.02 431 465 A22-M-B29 1A 2.47 428 466 A22-M-B30 1A 2.56 455 467 A22-M-B31 1A 2.43 439 468 A22-M-B33 1A 2.46 383 469 A22-M-B34 1A 3.03 439 470 A22-M-B35 1A 3.29 423 471 A22-M-B36 1A 2.66 395 472 A22-M-B66 1A 3.25 431 473 A22-M-B37 1A 2.44 409 474 A22-M-B38 1A 2.64 423 475 A22-M-B39 1A 3 439 476 A22-M-B40 1A 3.02 431 477 A22-M-B41 1A 2.82 455 478 A22-M-B42 1A 2.72 455 479 A22-M-B67 1A 3.07 455 480 A22-M-B43 1A 2.46 383 481 A22-M-B44 1A 2.11 397 482 A22-M-B45 1A 2.16 454 483 A22-M-B46 1A 2.62 437 484 A22-M-B47 1A 1.98 355 485 A22-M-B48 1A 2.61 383 486 A22-M-B49 1A 2.25 369 487 A22-M-B51 1A 2.74 421 488 A22-M-B52 1A 1.76 341 489 A22-M-B54 1A 2.75 421 490 A22-M-B59 1A 3.1 435 491 A23-M-B14 1A 3.04 496 492 A23-M-B15 1A 3.02 449 493 A23-M-B16 1A 2.76 435 494 A23-M-B17 1A 3.65 499 495 A23-M-B18 1A 3.2 489 496 A23-M-B64 1A 2.5 472 497 A23-M-B20 1A 3.04 477 498 A23-M-B22 1A 3.28 485 499 A23-M-B23 1A 3.46 485 500 A23-M-B24 1A 3.42 485 501 A23-M-B25 1A 3.53 477 502 A23-M-B26 1A 3.33 465 503 A23-M-B27 1A 3.16 451 504 A23-M-B28 1A 3.56 499 505 A23-M-B29 1A 3.04 496 506 A23-M-B30 1A 3.13 523 507 A23-M-B31 1A 2.99 507 508 A23-M-B33 1A 3.12 451 509 A23-M-B34 1A 3.59 507 510 A23-M-B35 1A 3.77 491 511 A23-M-B36 1A 3.29 463 512 A23-M-B66 1A 3.73 499 513 A23-M-B37 1A 3.06 477 514 A23-M-B38 1A 3.24 491 515 A23-M-B39 1A 3.56 507 516 A23-M-B40 1A 3.57 499 517 A23-M-B41 1A 3.39 523 518 A23-M-B42 1A 3.31 523 519 A23-M-B67 1A 3.58 523 520 A23-M-B43 1A 3.14 451 521 A23-M-B44 1A 2.7 465 522 A23-M-B45 1A 2.73 522 523 A23-M-B46 1A 3.2 505 524 A23-M-B47 1A 2.6 423 525 A23-M-B48 1A 3.23 451 526 A23-M-B49 1A 2.88 437 527 A23-M-B50 1A 2.85 437 528 A23-M-B51 1A 3.33 489 529 A23-M-B52 1A 2.35 409 530 A23-M-B54 1A 3.34 489 531 A23-M-B59 1A 3.62 503 532 A11-M-B54 1A 2.95 423 533 A23-M-B61 1A 2.9 489 534 A24-M-B14 1A 3.19 492 535 A24-M-B15 1A 3.18 445 536 A24-M-B16 1A 2.92 431 537 A24-M-B17 1A 3.8 495 538 A24-M-B18 1A 3.33 485 539 A24-M-B64 1A 2.66 468 540 A24-M-B20 1A 3.2 473 541 A24-M-B22 1A 3.42 481 542 A24-M-B23 1A 3.59 481 543 A24-M-B24 1A 3.58 481 544 A24-M-B25 1A 3.67 473 545 A24-M-B26 1A 3.49 461 546 A24-M-B27 1A 3.32 447 547 A24-M-B28 1A 3.71 495 548 A24-M-B29 1A 3.19 492 549 A24-M-B30 1A 3.27 519 550 A24-M-B31 1A 3.14 503 551 A24-M-B33 1A 3.27 447 552 A24-M-B34 1A 3.74 503 553 A24-M-B35 1A 3.88 487 554 A24-M-B36 1A 3.44 459 555 A24-M-B66 1A 3.87 495 556 A24-M-B37 1A 3.23 473 557 A24-M-B38 1A 3.38 487 558 A24-M-B39 1A 3.7 503 559 A24-M-B40 1A 3.7 495 560 A24-M-B41 1A 3.54 519 561 A24-M-B42 1A 3.45 519 562 A24-M-B67 1A 3.71 519 563 A24-M-B43 1A 3.31 447 564 A24-M-B44 1A 2.87 461 565 A24-M-B45 1A 2.89 518 566 A24-M-B46 1A 3.34 501 567 A24-M-B47 1A 2.76 419 568 A24-M-B48 1A 3.38 447 569 A24-M-B49 1A 3.06 433 570 A24-M-B50 1A 3.03 433 571 A24-M-B52 1A 2.52 405 572 A24-M-B54 1A 3.49 485 573 A24-M-B59 1A 3.76 499 574 A24-M-B60 1A 3.09 485 575 A25-M-B14 1A 3.23 492 576 A25-M-B15 1A 3.23 445 577 A25-M-B16 1A 2.97 431 578 A25-M-B17 1A 3.81 495 579 A25-M-B18 1A 3.37 485 580 A25-M-B64 1A 2.71 468 581 A25-M-B20 1A 3.24 473 582 A25-M-B22 1A 3.47 481 583 A25-M-B23 1A 3.63 481 584 A25-M-B24 1A 3.62 481 585 A25-M-B25 1A 3.7 473 586 A25-M-B26 1A 3.53 461 587 A25-M-B27 1A 3.36 447 588 A25-M-B28 1A 3.73 495 589 A25-M-B29 1A 3.23 492 590 A25-M-B30 1A 3.33 519 591 A25-M-B31 1A 3.2 503 592 A25-M-B33 1A 3.33 447 593 A25-M-B34 1A 3.77 503 594 A25-M-B35 1A 3.92 487 595 A25-M-B36 1A 3.48 459 596 A25-M-B66 1A 3.89 495 597 A25-M-B37 1A 3.27 473 598 A25-M-B38 1A 3.41 487 599 A25-M-B39 1A 3.74 503 600 A25-M-B40 1A 3.73 495 601 A25-M-B42 1A 3.49 519 602 A25-M-B67 1A 3.75 519 603 A25-M-B43 1A 3.36 447 604 A25-M-B44 1A 2.92 461 605 A25-M-B45 1A 2.93 518 606 A25-M-B46 1A 3.38 501 607 A25-M-B47 1A 2.83 419 608 A25-M-B48 1A 3.43 447 609 A25-M-B49 1A 3.11 433 610 A25-M-B50 1A 3.09 433 611 A25-M-B52 1A 2.58 405 612 A25-M-B54 1A 3.52 485 613 A25-M-B59 1A 3.78 499 614 A25-M-B68 1A 2.92 471 615 A25-M-B61 1A 3.08 485 616 A26-M-B14 1A 3.39 484 617 A26-M-B15 1A 3.43 437 618 A26-M-B16 1A 3.17 423 619 A26-M-B17 1A 3.97 487 620 A26-M-B18 1A 3.53 477 621 A26-M-B64 1A 2.89 460 622 A26-M-B20 1A 3.42 465 623 A26-M-B22 1A 3.64 473 624 A26-M-B23 1A 3.79 473 625 A26-M-B24 1A 3.78 473 626 A26-M-B25 1A 3.88 465 627 A26-M-B27 1A 3.54 439 628 A26-M-B28 1A 3.88 487 629 A26-M-B29 1A 3.38 484 630 A26-M-B30 1A 3.47 511 631 A26-M-B31 1A 3.35 495 632 A26-M-B33 1A 3.51 439 633 A26-M-B34 1A 3.93 495 634 A26-M-B35 1A 4.07 479 635 A26-M-B36 1A 3.66 451 636 A26-M-B66 1A 4.04 487 637 A26-M-B37 1A 3.45 465 638 A26-M-B38 1A 3.58 479 639 A26-M-B39 1A 3.9 495 640 A26-M-B40 1A 3.89 487 641 A26-M-B41 1A 3.74 511 642 A26-M-B42 1A 3.65 511 643 A26-M-B67 1A 3.89 511 644 A26-M-B43 1A 3.56 439 645 A26-M-B45 1A 3.11 510 646 A26-M-B46 1A 3.54 494 647 A26-M-B47 1A 3.03 411 648 A26-M-B48 1A 3.6 439 649 A26-M-B49 1A 3.3 425 650 A26-M-B50 1A 3.27 425 651 A26-M-B52 1A 2.78 397 652 A26-M-B54 1A 3.7 477 653 A26-M-B59 1A 3.95 491 654 A26-M-B61 1A 3.25 477 655 A27-M-B14 1A 3.14 470 656 A27-M-B15 1A 3.12 423 657 A27-M-B16 1A 2.86 409 658 A27-M-B17 1A 3.77 473 659 A27-M-B18 1A 3.29 463 660 A27-M-B64 1A 2.58 446 661 A27-M-B20 1A 3.15 451 662 A27-M-B22 1A 3.38 459 663 A27-M-B23 1A 3.56 459 664 A27-M-B24 1A 3.55 459 665 A27-M-B25 1A 3.63 451 666 A27-M-B26 1A 3.45 439 667 A27-M-B27 1A 3.27 425 668 A27-M-B28 1A 3.67 473 669 A27-M-B29 1A 3.14 470 670 A27-M-B30 1A 3.23 497 671 A27-M-B31 1A 3.1 481 672 A27-M-B33 1A 3.22 425 673 A27-M-B34 1A 3.7 481 674 A27-M-B35 1A 3.87 465 675 A27-M-B36 1A 3.39 437 676 A27-M-B66 1A 3.83 473 677 A27-M-B37 1A 3.16 451 678 A27-M-B38 1A 3.33 465 679 A27-M-B39 1A 3.67 481 680 A27-M-B40 1A 3.67 473 681 A27-M-B41 1A 3.5 497 682 A27-M-B42 1A 3.4 497 683 A27-M-B67 1A 3.69 497 684 A27-M-B43 1A 3.26 425 685 A27-M-B44 1A 2.8 439 686 A27-M-B45 1A 2.82 496 687 A27-M-B46 1A 3.29 479 688 A27-M-B47 1A 2.7 397 689 A27-M-B48 1A 3.33 425 690 A27-M-B49 1A 2.99 411 691 A27-M-B50 1A 2.97 411 692 A27-M-B51 1A 3.45 463 693 A27-M-B54 1A 3.45 463 694 A27-M-B59 1A 3.73 477 695 A27-M-B60 1A 3.03 463 696 A11-M-B59 1A 3.28 437 697 A1-M-B15 1A 2.86 397 698 A1-M-B16 1A 2.59 383 699 A1-M-B17 1A 3.55 447 700 A1-M-B18 1A 3.05 437 701 A1-M-B20 1A 2.89 425 702 A1-M-B22 1A 3.14 433 703 A1-M-B23 1A 3.33 433 704 A1-M-B24 1A 3.32 433 705 A1-M-B25 1A 3.41 425 706 A1-M-B26 1A 3.21 413 707 A1-M-B27 1A 3.02 399 708 A1-M-B28 1A 3.45 447 709 A1-M-B29 1A 2.89 444 710 A1-M-B30 1A 2.99 471 711 A1-M-B33 1A 2.97 399 712 A1-M-B65 1A 3.23 455 713 A1-M-B34 1A 3.48 455 714 A11-M-B60 1A 2.56 423 715 A1-M-B36 1A 3.14 411 716 A1-M-B66 1A 3.63 447 717 A1-M-B37 1A 2.91 425 718 A1-M-B38 1A 3.09 439 719 A1-M-B39 1A 3.45 455 720 A11-M-B61 1A 2.53 423 721 A1-M-B41 1A 3.26 471 722 A1-M-B42 1A 3.17 471 723 A1-M-B43 1A 3 399 724 A1-M-B45 1A 2.57 470 725 A1-M-B46 1A 3.06 453 726 A1-M-B47 1A 2.42 371 727 A1-M-B48 1A 3.08 399 728 A1-M-B49 1A 2.72 385 729 A1-M-B51 1A 3.2 437 730 A1-M-B52 1A 2.16 357 731 A1-M-B54 1A 3.21 437 732 A1-M-B59 1A 3.52 451 733 A1-M-B60 1A 2.79 437 734 A28-M-B17 1A 3.03 405 735 A28-M-B25 1A 2.82 383 736 A28-M-B26 1A 2.56 371 737 A28-M-B28 1A 2.89 405 738 A28-M-B29 1A 2.34 402 739 A28-M-B30 1A 2.44 429 740 A28-M-B31 1A 2.3 413 741 A28-M-B33 1A 2.33 357 742 A28-M-B65 1A 2.64 413 743 A28-M-B34 1A 2.86 413 744 A28-M-B35 1A 3.15 397 745 A28-M-B66 1A 3.12 405 746 A28-M-B37 1A 2.3 383 747 A28-M-B39 1A 2.85 413 748 A28-M-B40 1A 2.89 405 749 A28-M-B41 1A 2.68 429 750 A28-M-B42 1A 2.57 429 751 A28-M-B67 1A 2.91 429 752 A28-M-B45 1A 2.04 428 753 A28-M-B52 1A 1.67 315 754 A28-M-B1 1A 2.41 377 755 A28-M-B54 1A 2.6 395 756 A28-M-B59 1A 2.97 409 757 A11-M-B14 1A 2.65 430 758 A11-M-B15 1A 2.58 383 759 A11-M-B17 1A 3.33 433 760 A11-M-B18 1A 2.8 423 761 A11-M-B20 1A 2.63 411 762 A11-M-B22 1A 2.87 419 763 A11-M-B23 1A 3.08 419 764 A11-M-B24 1A 3.07 419 765 A11-M-B25 1A 3.15 411 766 A11-M-B26 1A 2.92 399 767 A11-M-B27 1A 2.74 385 768 A11-M-B28 1A 3.21 433 769 A11-M-B29 1A 2.65 430 770 A11-M-B30 1A 2.74 457 771 A25-M-B41 1A 3.58 519 772 A14-M-B70 2 5.28 546 773 A14-M-B71 2 4.76 467

Example 2

Preparation of A2-M-B9

A sulfonyl chloride of formula (X), wherein R^(a) corresponds to fragment B9 of table II, (0.12 mmol, 1.2 eq.) was added to a suspension of the resin of example 8 wherein Rc corresponds to the fragment A2 of table I (0 1 mmol, 1 eq.) in dry DCM (2.5 ml) and N-methyl morpholine (22.0 μl, 0.2 mmol, 2 eq.). The final suspension was shaken overnight at 25° C. in a reactor (Quest 210™ or Miniblocks™). The resin was washed sequentially with DMF (1 ml), DCM (1 ml), DMF (1 ml), DCM (1 ml), MeOH (1 ml), water (1 ml), MeOH (1 ml), DCM (1 ml), MeOH (1 ml), DCM (1 ml), MeOH (1 ml), MTBE (1 ml, 2 cycles) and then air dried. The Resin (0.1 mmol, 1 eq.) was suspended in a solution of TFA/DCM 1:1 (2 ml) and shaken for 2 h at 25° C. The solution phase was collected and the resin was rinsed with DCM (collected as well), and a second cycle was performed. The final washing was performed with MeOH. All the collected were dried under reduced pressure affording compound A2-M-B9 (see entry 774 of table IV below).

LCMS (HPLC Method 1B): m/z 519 [M+H]⁺ @ r.t. 3.2 min ¹H NMR (400 MHz, DMSO-d₆) δ ppm 8.03 (d, J=5.0 Hz, 1H), 7.86 (t, J=5.4 Hz, 1H), 7.66-7.72 (m, 2H), 7.56-7.61 (m, 2H), 7.37 (d, J=8.9 Hz, 1H), 7.33 (d, J=1.8 Hz, 1H), 6.99 (dd, J=9.0, 2.0 Hz, 1H), 6.96 (s, 1H), 4.91-5.00 (m, 1H), 3.77 (dd, J=13.0, 4.5 Hz, 1H), 3.42-3.49 (m, 1H), 2.85-2.94 (m, 2H), 2.38-2.58 (m, 2H), 2.13 (br. s., 8H), 1.29-1.40 (m, 2H).

Following the procedure described in example 10 and by using any proper reactant as per the process of the invention that is, by supporting any suitable amine onto the resin, by sulfonylation the amino function in position 8 of the 3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one moiety with any suitable sulfonyl chloride derivative and by finally carrying out resin cleavage, the following compounds of table IV were also prepared.

TABLE IV HPLC HPLC Entry Compound Method tR (min) [M + H]+ 774 A2-M-B9 1B 3.2 519 775 A2-M-B10 1B 2.51 490 776 A2-M-B11 1B 2.79 520 777 A3-M-B9 1B 3.25 547 778 A3-M-B10 1B 2.55 518 779 A3-M-B11 1B 2.83 548 780 A4-M-B9 1B 4.46 491 781 A4-M-B10 1B 3.54 463 782 A4-M-B11 1B 3.94 493 783 A5-M-B9 1B 5.45 538 784 A5-M-B13 1B 4.72 509 785 A5-M-B10 1B 4.69 509 786 A5-M-B11 1B 5.04 539 787 A6-M-B9 1B 5.42 504 788 A6-M-B10 1B 4.6 475 789 A6-M-B11 1B 4.97 505 790 A7-M-B9 1B 4.67 473 791 A7-M-B10 1B 3.73 445 792 A7-M-B11 1B 4.14 475 793 A10-M-B19 1A 1.87 421 794 A10-M-B21 1A 2.74 497 795 A10-M-B32 1A 2.02 435 796 A11-M-B32 1A 2.03 393 797 A10-M-B55 1A 2.65 518 798 A10-M-B62 1A 2.95 515 799 A10-M-B63 1A 2.95 519 800 A13-M-B19 1A 1.84 379 801 A13-M-B21 1A 2.78 455 802 A13-M-B32 1A 1.99 393 803 A13-M-B55 1A 2.68 475 804 A13-M-B62 1A 3 473 805 A13-M-B63 1A 3.01 477 806 A14-M-B19 1A 2.26 427 807 A14-M-B21 1A 3.12 503 808 A14-M-B32 1A 2.42 441 809 A14-M-B55 1A 3.06 524 810 A14-M-B62 1A 3.32 521 811 A14-M-B63 1A 3.33 525 812 A15-M-B19 1A 2.04 393 813 A15-M-B21 1A 2.97 469 814 A15-M-B32 1A 2.21 407 815 A15-M-B55 1A 2.87 489 816 A15-M-B62 1A 3.19 487 817 A15-M-B63 1A 3.21 491 818 A16-M-B19 1A 2.11 405 819 A16-M-B21 1A 3.04 481 820 A16-M-B32 1A 2.29 419 821 A16-M-B69 1A 2.96 481 822 A16-M-B55 1A 2.94 502 823 A16-M-B62 1A 3.25 499 824 A16-M-B63 1A 3.28 503 825 A17-M-B19 1A 1.99 417 826 A17-M-B21 1A 2.88 493 827 A17-M-B32 1A 2.15 431 828 A17-M-B62 1A 3.09 511 829 A17-M-B63 1A 3.09 515 830 A18-M-B21 1A 3.26 517 831 A18-M-B32 1A 2.62 455 832 A18-M-B55 1A 3.18 538 833 A18-M-B62 1A 3.45 535 834 A18-M-B63 1A 3.48 539 835 A4-M-B19 1A 1.73 395 836 A4-M-B21 1A 2.6 471 837 A4-M-B32 1A 1.88 409 838 A4-M-B69 1A 2.49 471 839 A4-M-B55 1A 2.51 491 840 A4-M-B62 1A 2.82 489 841 A4-M-B63 1A 2.8 493 842 A19-M-B19 1A 1.72 365 843 A19-M-B21 1A 2.63 441 844 A19-M-B32 1A 1.87 379 845 A20-M-B19 1A 2.68 433 846 A20-M-B21 1A 3.45 509 847 A20-M-B32 1A 2.84 447 848 A20-M-B69 1A 3.48 509 849 A20-M-B55 1A 3.36 530 850 A20-M-B62 1A 3.63 527 851 A20-M-B63 1A 3.74 531 852 A7-M-B19 1A 1.8 377 853 A7-M-B21 1A 2.73 453 854 A7-M-B32 1A 1.96 391 855 A7-M-B55 1A 2.63 473 856 A7-M-B62 1A 2.95 471 857 A7-M-B63 1A 2.95 475 858 A21-M-B19 1A 2.36 445 859 A21-M-B21 1A 3.21 521 860 A21-M-B32 1A 2.54 459 861 A21-M-B55 1A 3.15 542 862 A21-M-B62 1A 3.39 539 863 A21-M-B63 1A 3.4 543 864 A22-M-B19 1A 1.72 377 865 A22-M-B21 1A 2.63 453 866 A22-M-B32 1A 1.87 391 867 A22-M-B55 1A 2.54 473 868 A22-M-B62 1A 2.85 471 869 A22-M-B63 1A 2.83 475 870 A23-M-B19 1A 2.33 445 871 A23-M-B21 1A 3.16 521 872 A23-M-B32 1A 2.5 459 873 A23-M-B55 1A 3.1 542 874 A23-M-B62 1A 3.34 539 875 A23-M-B63 1A 3.38 543 876 A24-M-B19 1A 2.5 441 877 A24-M-B21 1A 3.3 517 878 A24-M-B32 1A 2.66 455 879 A24-M-B69 1A 3.24 517 880 A24-M-B55 1A 3.23 538 881 A11-M-B55 1A 2.71 475 882 A24-M-B62 1A 3.48 535 883 A24-M-B63 1A 3.51 539 884 A25-M-B19 1A 2.57 441 885 A25-M-B21 1A 3.36 517 886 A25-M-B32 1A 2.72 455 887 A25-M-B55 1A 3.28 538 888 A25-M-B62 1A 3.53 535 889 A25-M-B63 1A 3.57 539 890 A26-M-B19 1A 2.75 433 891 A26-M-B21 1A 3.5 509 892 A26-M-B32 1A 2.9 447 893 A26-M-B55 1A 3.46 530 894 A26-M-B62 1A 3.7 527 895 A26-M-B63 1A 3.73 531 896 A27-M-B19 1A 2.38 419 897 A27-M-B21 1A 3.25 495 898 A27-M-B32 1A 2.57 433 899 A27-M-B55 1A 3.18 516 900 A27-M-B62 1A 3.45 513 901 A27-M-B63 1A 3.48 517 902 A1-M-B19 1A 2.13 393 903 A1-M-B21 1A 3.04 469 904 A1-M-B32 1A 2.3 407 905 A11-M-B62 1A 3.02 473 906 A1-M-B55 1A 2.96 489 907 A1-M-B62 1A 3.25 487 908 A1-M-B63 1A 3.28 491 909 A28-M-B19 1A 1.64 351 910 A28-M-B21 1A 2.52 427 911 A28-M-B32 1A 1.79 365 912 A28-M-B55 1A 2.42 447 913 A28-M-B63 1A 3.1 449 914 A11-M-B19 1A 1.87 379 915 A11-M-B63 1A 3.03 477 916 A11-M-B21 1A 2.81 455 917 A14-M-B72 2 5.33 557

Example 3

Preparation of A7-M-B6

An isocyanate of formula (IX), wherein R^(a) corresponds to fragment B6 of table II, (0.3 mmol, 3 eq.) was added to a suspension of the resin of example 8 wherein R^(c) corresponds to the fragment A7 of table I (0.1 mmol, 1 eq.) in dry DCM (2.5 ml) and DIPEA (17.1 μl, 0.1 mmol, 1 eq.). The final suspension was shaken overnight at 25° C. in a reactor (Quest 210™ or Miniblocks™). The resin was washed sequentially with DMF (1 ml), DCM (1 ml), DMF (1 ml), DCM (1 ml), MeOH (1 ml), water (1 ml), MeOH (1 ml), DCM (1 ml), MeOH (1 ml), DCM (1 ml), MeOH (1 ml), MTBE (1 ml, 2 cycles) and then air dried. The Resin (0.1 mmol, 1 eq.) was suspended in a solution of TFA/DCM 1:1 (2 ml) and shaken for 2 h at 25° C. The solution phase was collected and the resin was rinsed with DCM (collected as well), and a second cycle was performed. The final washing was performed with MeOH. All the collected were dried under reduced pressure affording compound A7-M-B6 (see entry 937 of table V below).

LCMS (HPLC Method 1B): m/z 448 [M+H]⁺ @ r.t. 4.3 min. ¹H NMR (400 MHz, DMSO-d₆) 8 ppm 8.51 (s, 1H), 8.46 (s, 1H), 8.11 (t, J=5.6 Hz, 1H), 8.00 (d, J=5.0 Hz, 1H), 7.83 (d, J=1.7 Hz, 1H), 7.43 (d, J=8.9 Hz, 1H), 7.34-7.39 (m, 2H), 7.24 (dd, J=9.0, 2.0 Hz, 1H), 6.97 (s, 1H), 6.84-6.89 (m, 2H), 5.59-5.71 (m, 1H), 4.95-5.04 (m, 3H), 3.83 (dd, J=12.9, 4.0 Hz, 1H), 3.72 (s, 3H), 3.60-3.65 (m, 2H), 3.49 (dd, J=13.4, 5.2 Hz, 1H), 2.57-2.64 (m, 1H), 2.46-2.53 (m, 1H).

Following the procedure described in example 11 and by using any proper reactant as per the process of the invention, that is by supporting any suitable amine onto the resin, by preparing the carbamate derivative in position 8 of the 3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one moiety with any suitable isocyanate derivative and by finally carrying out resin cleavage, the following compounds of table V were also prepared.

TABLE V HPLC HPLC Entry Compound Method tR (min) [M + H]+ 918 A2-M-B5 1B 3.16 469 919 A2-M-B6 1B 2.93 493 920 A2-M-B7 1B 3.14 491 921 A3-M-B5 1B 3.23 497 922 A3-M-B6 1B 2.99 521 923 A3-M-B7 1B 3.22 519 924 A4-M-B5 1B 4.6 442 925 A4-M-B6 1B 4.09 466 926 A4-M-B7 1B 4.57 464 927 A4-M-B8 1B 5.46 504 928 A5-M-B5 1B 5.66 488 929 A5-M-B6 1B 5.15 512 930 A5-M-B7 1B 5.61 510 931 A5-M-B8 1B 6.23 550 932 A6-M-B5 1B 5.63 454 933 A6-M-B6 1B 5.12 478 934 A6-M-B7 1B 5.58 476 935 A6-M-B8 1B 6.23 516 936 A7-M-B5 1B 4.84 424 937 A7-M-B6 1B 4.3 448 938 A7-M-B7 1B 4.8 446 939 A7-M-B8 1B 5.65 486 940 A8-M-B5 1B 3.26 469 941 A8-M-B7 1B 3.26 491 942 A9-M-B7 1B 3.36 497 943 A10-M-B5 1A 3.06 468 944 A10-M-B53 1A 2.75 454 945 A10-M-B56 1A 2.68 442 946 A10-M-B57 1A 1.86 400 947 A10-M-B58 1A 2.04 444 948 A13-M-B5 1A 3.13 426 949 A13-M-B53 1A 2.82 412 950 A13-M-B56 1A 2.74 400 951 A13-M-B57 1A 1.85 358 952 A13-M-B58 1A 2.05 402 953 A14-M-B5 1A 3.48 474 954 A14-M-B53 1A 3.21 460 955 A14-M-B56 1A 3.13 448 956 A14-M-B57 1A 2.26 406 957 A15-M-B5 1A 3.36 440 958 A15-M-B56 1A 2.97 414 959 A15-M-B57 1A 2.06 372 960 A16-M-B5 1A 3.43 452 961 A16-M-B53 1A 3.13 438 962 A16-M-B56 1A 3.06 426 963 A16-M-B57 1A 2.14 384 964 A16-M-B58 1A 2.33 428 965 A17-M-B5 1A 3.24 464 966 A17-M-B53 1A 2.94 450 967 A17-M-B56 1A 2.86 438 968 A17-M-B57 1A 2 396 969 A17-M-B58 1A 2.18 440 970 A18-M-B5 1A 3.61 488 971 A18-M-B53 1A 3.36 474 972 A18-M-B56 1A 3.31 462 973 A18-M-B57 1A 2.46 420 974 A18-M-B58 1A 2.57 464 975 A4-M-B53 1A 2.62 428 976 A4-M-B56 1A 2.52 416 977 A4-M-B57 1A 1.73 374 978 A19-M-B5 1A 2.97 412 979 A19-M-B53 1A 2.63 398 980 A19-M-B56 1A 2.56 386 981 A19-M-B57 1A 1.73 344 982 A19-M-B58 1A 1.92 388 983 A20-M-B5 1A 3.9 480 984 A20-M-B53 1A 3.68 466 985 A20-M-B56 1A 3.63 454 986 A20-M-B58 1A 2.96 456 987 A7-M-B53 1A 2.76 410 988 A7-M-B57 1A 1.81 356 989 A7-M-B58 1A 2.01 400 990 A21-M-B5 1A 3.58 492 991 A21-M-B53 1A 3.33 478 992 A21-M-B56 1A 3.24 466 993 A21-M-B57 1A 2.36 424 994 A21-M-B58 1A 2.55 468 995 A22-M-B5 1A 2.98 424 996 A22-M-B53 1A 2.65 410 997 A22-M-B56 1A 2.56 398 998 A22-M-B57 1A 1.74 356 999 A11-M-B53 1A 2.85 412 1000 A23-M-B5 1A 3.52 492 1001 A23-M-B53 1A 3.27 478 1002 A23-M-B56 1A 3.2 466 1003 A23-M-B57 1A 2.32 424 1004 A23-M-B58 1A 2.51 468 1005 A24-M-B5 1A 3.66 488 1006 A24-M-B53 1A 3.42 474 1007 A24-M-B57 1A 2.5 420 1008 A24-M-B58 1A 2.67 464 1009 A25-M-B5 1A 3.71 488 1010 A25-M-B53 1A 3.46 474 1011 A25-M-B56 1A 3.4 462 1012 A25-M-B57 1A 2.56 420 1013 A25-M-B58 1A 2.72 464 1014 A26-M-B5 1A 3.89 480 1015 A11-M-B56 1A 2.77 400 1016 A11-M-B57 1A 1.89 358 1017 A26-M-B53 1A 3.65 466 1018 A26-M-B56 1A 3.6 454 1019 A26-M-B57 1A 2.76 412 1020 A26-M-B58 1A 2.92 456 1021 A27-M-B5 1A 3.64 466 1022 A27-M-B53 1A 3.38 452 1023 A27-M-B56 1A 3.31 440 1024 A27-M-B57 1A 2.41 398 1025 A27-M-B58 1A 2.59 442 1026 A11-M-B58 1A 2.09 402 1027 A1-M-B5 1A 3.43 440 1028 A1-M-B53 1A 3.13 426 1029 A1-M-B56 1A 3.05 414 1030 A1-M-B57 1A 2.14 372 1031 A1-M-B58 1A 2.34 416 1032 A28-M-B5 1A 2.84 398 1033 A28-M-B53 1A 2.51 384 1034 A28-M-B57 1A 1.64 330 1035 A28-M-B58 1A 1.83 374 1036 A11-M-B5 1A 3.16 426 1037 A14-M-B73 2 4.53 482 1038 A14-M-B74 2 3.83 434

Example 4

Preparation of A14-M-B76

An aldehyde of formula (XIII, wherein R^(a) corresponds to the fragment B76 of table II, (1.0 mmol, 10 eq.) was added to a suspension of the resin of example 8 wherein R^(c) corresponds to the fragment A14 of table I (0.1 mmol, 1 eq.) in a dry mixture CH(OCH3)₃/DMF/MeOH 9:1:2 (2 ml) and acetic acid (20 μl). The final suspension was shaken overnight at 25° C. in a reactor (Quest 210™ or Miniblocks™). The resin was washed sequentially with DMF (1 ml), DCM (1 ml), DMF (1 ml), DCM (1 ml). The Resin (0.1 mmol, 1 eq.) was suspended in THF, NaCNBH₃ (314 mg, 5.0 mmol, 50 eq.) was added and the final suspension was shaken for 16 h at 25° C. The resin was washed sequentially with DMF (1 ml), DCM (1 ml), DMF (1 ml), DCM (1 ml), MeOH (1 ml), water (1 ml), MeOH (1 ml), DCM (1 ml), MeOH (1 ml), DCM (1 ml), MeOH (1 ml), MTBE (1 ml, 2 cycles) and then air dried. The Resin (0 1 mmol, 1 eq.) was suspended in a solution of TFA/DCM 1:1 (2 ml) and shaken for 2 h at 25° C. The solution phase was collected and the resin was rinsed with DCM (collected as well), and a second cycle was performed. The final washing was performed with MeOH. All the collected were dried under reduced pressure affording compound A14-M-B76 (see entry 1039 of table VI below).

LCMS (HPLC Method 2): m/z 517 [M+H]⁺ @ r.t. 5.91 min ¹H NMR (400 MHz, DMSO-d₆) δ ppm 8.40 (t, J=5.7 Hz, 2 H), 7.87-8.04 (m, 2 H), 7.27-7.33 (m, 2 H), 7.01 (dd, J=7.6, 1.6 Hz, 3 H), 4.88-5.08 (m, 2 H), 4.38 (s, 3 H), 4.06-4.26 ppm (m, 4 H).

Following the procedure described in example 12 and by using any proper reactant as per the process of the invention, that is by supporting any suitable amine onto the resin, by preparing the amino derivative in position 8 of the 3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one moiety with any suitable aldehyde derivative and by finally carrying out resin cleavage, the following compounds of table VI were also prepared.

TABLE VI HPLC HPLC Entry Compound Method tR (min) [M + H]+ 1039 A14-M-B75 2 6.27 445 1040 A14-M-B76 2 5.91 517 

The invention claimed is:
 1. A method for treating a disease caused by and/or associated with a dysregulated protein kinase activity which comprises administering to a mammal in need thereof an effective amount of a compound of formula (I)

wherein R is selected from the group consisting of —R^(a), —COR^(a), —CONR^(a)R^(b), —SO₂R^(a) and —COOR^(a), and R1 is a group —NR^(c)R^(d) or —OR^(c ,) wherein R^(a), R^(b),R^(c) and R^(d), the same or different, are each independently hydrogen or a group optionally further substituted, selected from straight or branched C₁-C₆ alkyl, C₂-C₆ alkenyl or C₂-C₆ alkynyl, C₃-C₆ cycloalkyl or cycloalkyl C₁-C₆ alkyl, heterocyclyl or heterocyclyl C₁-C₆ alkyl, aryl or aryl C₁-C₆ alkyl, heteroaryl or heteroaryl C₁-C₆ alkyl or, taken together with the nitrogen atom to which they are bonded, either R^(a) and R^(b) as well as R^(c) and R^(d) may form an optionally substituted 3 to 7 membered heterocyclyl or heteroaryl, optionally containing one additional heteroatom or heteroatomic group selected from S, O, N or NH, and pharmaceutically acceptable salts thereof, wherein the disease is selected from the group consisting of ovarian cancer and breast cancer.
 2. An in vitro method for inhibiting protein kinase activity which comprises contacting the kinase with an effective amount of a compound of formula (I)

wherein R is selected from the group consisting of —R^(a), —COR, —CONR^(a)R^(b), —SO₂R^(a) and —COOR^(a), and R1 is a group —NR^(c)R^(d) or —OR^(c), wherein R^(a),R^(b), R^(c) and R^(d), the same or different, are each independently hydrogen or a group optionally further substituted, selected from straight or branched C₁-C₆ alkyl, C₂-C₆, alkenyl or C₂-C₆ alkynyl, C₃-C₆ cycloalkyl or cycloalkyl C₁-C₆ alkyl, heterocyclyl or heterocyclyl C₁-C₆ alkyl, aryl or aryl C₁-C₆ alkyl, heteroaryl or heteroaryl C₁C₆ alkyl or, taken together with the nitrogen atom to which they are bonded, either R^(a) and R^(b) as well as R^(c) and R^(d) may form an optionally substituted 3 to 7 membered heterocyclyl or heteroaryl, optionally containing one additional heteroatom or heteroatomic group selected from S, O, N or NH, and pharmaceutically acceptable salts thereof, wherein the kinase is selected from the group consisting of LCK, EGFR1, JAK2, ROS1, FGFR1, ALK, ABL, AUR1, AUR2, CDK2/CYCA, IGFR1, IR, KIT, MET, NEK6, TRKA, and VEGFR3. 